Considérez une liste aléatoire des entiers de 1 à N. Vous voulez la trier en utilisant uniquement les actions suivantes:

1. Échangez les premier et dernier éléments de la liste. (S)
2. Pop off le premier élément et l' ajouter à la fin de la liste. (P)

Ceci est toujours possible car n'importe quelle liste peut être triée avec suffisamment d'échanges d'éléments adjacents. En utilisant S et P, vous pouvez échanger tous les éléments adjacents en appelant P jusqu'à ce que les deux éléments en question soient le premier et le dernier élément de la liste, puis en appelant S pour les échanger, puis en appelant à nouveau P jusqu'à ce qu'ils se trouvent dans les index d'origine (maintenant échangés ).

Pourtant, en termes de nombre d'opérations S et P, il est peu probable que cette méthode soit optimale pour la plupart des listes.

Défi

Écrivez un programme ou une fonction qui accepte une permutation des nombres de 1 à N (N> 1). Il peut être donné sous forme de liste ou de chaîne ou tout ce qui est pratique. Il devrait produire une séquence de S et de P qui trierait la permutation lorsqu'elle est appliquée de gauche à droite. Il n'est pas nécessaire que cette séquence soit courte de manière optimale, mais plus courte est la meilleure (voir Scoring).

Exemple

Si l'entrée était [2, 1, 3]la sortie, c'est peut-être SPparce que

• S appliqué à [2, 1, 3] fait [3, 1, 2],
• et P appliqué à [3, 1, 2] fait [1, 2, 3], qui est trié.

Vérifieur

Cet extrait de pile peut être utilisé pour vérifier qu'une séquence trie vraiment la liste. La liste doit avoir des crochets et être séparée par des virgules. La séquence SP n'est qu'une chaîne de S«et P».

<style>*{font-family:monospace}</style><script>function swap(list) {var tmp = list[0];list[0] = list[list.length - 1];list[list.length - 1] = tmp;}function pop(list) {list.push(list.shift())}function check() {var result = 'Sorted sucessfully.';var details = '';try {var list = eval(document.getElementById('list').value);var seq = document.getElementById('seq').value;details += 'Sequence: ' + seq + '<br>Steps:<br>' + list + ' <-- original';for(var i = 0; i < seq.length; i++) {if (seq.charAt(i) == 'S')swap(list);else if (seq.charAt(i) == 'P')pop(list);details += ' (' + i + ')<br>' + list;}details += ' <-- final (' + i + ')';for(var i = 1; i < list.length; i++) {if (list[i-1] > list[i]) {result = 'Sorting failed!';break;}}} catch(e) {result = 'Error: ' + e;}document.getElementById('result').innerHTML = result;document.getElementById('details').innerHTML = details;}</script><p>List<br><input id='list'type='text'size='60'value='[2, 1, 3]'></p><p>SP Sequence<br><textarea id='seq'rows='1'cols='60'>SP</textarea><br></p><button type='button'onclick='check()'>Check</button><p id='result'></p><p id='details'></p>

Notation

Votre algorithme doit produire des séquences SP correctes, mais peut-être sous-optimales, pour N = 2 à 256. Pour toute permutation dans cette plage, il doit fonctionner en moins de 5 minutes sur un ordinateur moderne décent .

Votre score est le nombre total d'opérations S et P dont votre algorithme a besoin pour trier les 30 listes fournies ci-dessous. Le score le plus bas l'emporte.

Vous ne pouvez pas coder en dur votre programme en fonction de ces données. Si cela semble nécessaire, je peux ajouter plus de données de test pour déterminer le gagnant.

1. Length 3
[2, 1, 3]
2. Length 7
[2, 7, 5, 3, 4, 6, 1]
3. Length 41
[7, 12, 17, 2, 14, 15, 33, 20, 37, 18, 9, 25, 41, 26, 39, 29, 16, 5, 23, 24, 35, 38, 32, 6, 11, 21, 27, 8, 40, 3, 10, 36, 13, 30, 31, 28, 1, 4, 19, 22, 34]
4. Length 52
[19, 49, 34, 26, 38, 3, 14, 37, 21, 39, 46, 29, 18, 6, 15, 25, 28, 47, 22, 41, 32, 51, 50, 5, 45, 4, 30, 44, 10, 43, 20, 17, 13, 36, 48, 27, 35, 24, 8, 12, 40, 2, 1, 16, 7, 31, 23, 33, 42, 52, 9, 11]
5. Length 65
[12, 53, 4, 5, 17, 32, 58, 54, 18, 43, 21, 26, 51, 45, 9, 2, 35, 28, 40, 61, 57, 27, 62, 39, 24, 59, 36, 25, 20, 33, 63, 56, 64, 47, 38, 7, 13, 34, 16, 30, 49, 22, 37, 3, 48, 11, 52, 1, 29, 42, 50, 23, 6, 8, 60, 65, 46, 10, 41, 31, 44, 15, 14, 19, 55]
6. Length 69
[58, 15, 63, 18, 24, 59, 26, 37, 44, 67, 14, 52, 2, 31, 68, 54, 32, 17, 55, 50, 42, 56, 65, 29, 13, 41, 7, 45, 53, 35, 21, 39, 61, 23, 49, 12, 60, 46, 27, 57, 28, 40, 10, 69, 1, 6, 19, 62, 8, 30, 64, 34, 3, 43, 38, 20, 25, 33, 66, 47, 4, 36, 16, 11, 5, 22, 51, 48, 9]
7. Length 75
[14, 69, 1, 43, 32, 42, 59, 37, 70, 63, 57, 60, 56, 73, 67, 6, 11, 36, 31, 22, 40, 7, 21, 35, 50, 64, 28, 41, 18, 17, 75, 54, 51, 19, 68, 33, 45, 61, 66, 52, 49, 65, 4, 72, 23, 34, 9, 15, 38, 16, 3, 71, 29, 30, 48, 53, 10, 8, 13, 47, 20, 55, 74, 27, 25, 62, 46, 24, 44, 39, 2, 26, 58, 12, 5]
8. Length 80
[3, 65, 44, 14, 19, 6, 11, 29, 79, 35, 42, 16, 68, 7, 62, 30, 38, 46, 15, 9, 75, 5, 52, 32, 22, 70, 64, 13, 21, 47, 10, 4, 55, 40, 45, 56, 77, 27, 23, 72, 17, 71, 53, 20, 18, 25, 73, 59, 36, 34, 37, 57, 1, 69, 24, 58, 33, 76, 2, 12, 49, 61, 78, 67, 66, 63, 50, 80, 28, 48, 26, 51, 41, 60, 31, 54, 39, 8, 74, 43]
9. Length 103
[40, 62, 53, 6, 32, 85, 8, 83, 33, 29, 87, 93, 22, 37, 80, 12, 74, 69, 64, 9, 18, 98, 17, 45, 60, 38, 10, 103, 19, 5, 54, 15, 90, 100, 79, 91, 46, 82, 43, 31, 51, 96, 30, 70, 76, 16, 55, 77, 11, 65, 58, 75, 61, 3, 28, 24, 101, 20, 41, 72, 86, 56, 35, 50, 78, 27, 67, 95, 44, 68, 48, 26, 39, 97, 21, 49, 102, 73, 63, 7, 71, 52, 1, 88, 34, 42, 14, 47, 36, 99, 4, 13, 94, 89, 59, 92, 57, 25, 23, 66, 81, 2, 84]
10. Length 108
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108]
11. Length 109
[48, 89, 25, 64, 8, 69, 81, 98, 107, 61, 106, 63, 59, 50, 83, 24, 86, 68, 100, 104, 56, 88, 46, 62, 94, 4, 47, 33, 19, 1, 77, 102, 9, 30, 44, 26, 16, 80, 67, 75, 70, 96, 108, 45, 79, 51, 12, 38, 73, 37, 65, 31, 60, 22, 28, 3, 43, 71, 105, 91, 93, 101, 13, 97, 29, 72, 82, 87, 27, 5, 17, 10, 34, 84, 53, 15, 78, 41, 85, 6, 14, 57, 76, 7, 23, 99, 32, 95, 49, 2, 21, 109, 74, 39, 11, 103, 18, 90, 35, 40, 58, 20, 55, 52, 36, 54, 42, 92, 66]
12. Length 151
[61, 7, 8, 79, 78, 4, 48, 13, 14, 117, 12, 96, 130, 118, 63, 110, 72, 57, 86, 126, 62, 10, 29, 102, 99, 28, 56, 135, 11, 151, 141, 97, 45, 109, 38, 150, 40, 149, 52, 140, 106, 80, 66, 134, 125, 137, 31, 85, 68, 94, 36, 26, 95, 92, 49, 25, 120, 148, 33, 73, 41, 100, 58, 127, 60, 122, 133, 9, 19, 81, 59, 55, 103, 146, 42, 21, 128, 75, 101, 82, 50, 142, 131, 76, 20, 69, 139, 83, 16, 64, 17, 124, 90, 138, 37, 1, 34, 43, 129, 77, 23, 35, 144, 121, 113, 115, 114, 67, 98, 70, 145, 104, 71, 5, 119, 6, 18, 88, 116, 111, 132, 39, 89, 24, 15, 107, 27, 65, 30, 47, 143, 93, 53, 108, 2, 74, 123, 44, 51, 54, 87, 147, 84, 3, 112, 46, 32, 91, 136, 22, 105]
13. Length 173
[93, 14, 141, 125, 64, 30, 24, 85, 44, 68, 91, 22, 103, 155, 117, 114, 123, 51, 131, 72, 67, 61, 5, 41, 10, 20, 129, 86, 154, 108, 161, 2, 82, 153, 96, 50, 136, 121, 128, 126, 120, 111, 89, 113, 104, 84, 18, 109, 42, 83, 162, 124, 173, 116, 12, 54, 52, 39, 122, 49, 46, 1, 130, 71, 152, 73, 56, 34, 149, 75, 133, 8, 74, 45, 88, 23, 7, 60, 115, 134, 53, 119, 106, 81, 112, 31, 35, 172, 159, 38, 59, 69, 142, 146, 110, 170, 160, 166, 43, 58, 4, 107, 78, 156, 47, 33, 145, 63, 163, 27, 70, 77, 36, 16, 100, 26, 19, 151, 57, 32, 15, 13, 40, 169, 98, 132, 135, 62, 66, 90, 102, 171, 99, 148, 80, 144, 147, 168, 94, 143, 17, 3, 140, 97, 11, 65, 55, 92, 95, 127, 167, 150, 87, 118, 28, 137, 9, 29, 105, 157, 25, 165, 158, 21, 164, 101, 79, 76, 6, 138, 48, 37, 139]
14. Length 177
[68, 117, 61, 159, 110, 148, 3, 20, 169, 145, 136, 1, 120, 109, 21, 58, 52, 97, 65, 168, 34, 134, 111, 176, 13, 156, 172, 53, 55, 124, 177, 88, 92, 23, 72, 26, 104, 121, 133, 73, 39, 140, 25, 71, 119, 158, 146, 128, 18, 94, 113, 45, 60, 96, 30, 5, 116, 153, 90, 115, 67, 80, 112, 154, 9, 17, 10, 33, 81, 38, 95, 118, 35, 160, 151, 150, 76, 77, 14, 147, 173, 135, 162, 114, 27, 100, 167, 74, 69, 165, 108, 79, 91, 48, 105, 125, 129, 75, 93, 11, 12, 64, 24, 170, 142, 98, 44, 37, 43, 78, 16, 28, 166, 155, 138, 164, 122, 163, 107, 130, 86, 56, 2, 161, 63, 126, 131, 144, 82, 106, 103, 32, 132, 54, 41, 171, 70, 85, 19, 143, 137, 87, 84, 66, 99, 102, 15, 49, 123, 175, 89, 51, 141, 62, 50, 36, 152, 47, 42, 8, 7, 46, 29, 22, 149, 139, 4, 40, 83, 6, 59, 57, 174, 31, 127, 101, 157]
15. Length 192
[82, 130, 189, 21, 169, 147, 160, 66, 133, 153, 143, 116, 49, 13, 63, 61, 94, 164, 35, 112, 141, 62, 87, 171, 19, 3, 93, 83, 149, 64, 34, 170, 129, 182, 101, 77, 14, 91, 145, 23, 32, 92, 187, 54, 184, 120, 109, 159, 27, 44, 60, 103, 134, 52, 122, 33, 78, 88, 108, 45, 15, 79, 137, 80, 161, 69, 6, 139, 110, 67, 43, 190, 152, 59, 173, 125, 168, 37, 151, 132, 1, 178, 20, 114, 119, 144, 25, 146, 42, 136, 162, 123, 31, 107, 131, 127, 51, 105, 2, 65, 28, 102, 76, 24, 135, 174, 9, 111, 98, 39, 74, 142, 70, 121, 154, 38, 113, 75, 40, 86, 100, 106, 181, 117, 95, 85, 138, 41, 167, 172, 4, 186, 17, 16, 104, 71, 81, 73, 57, 8, 140, 118, 158, 12, 148, 53, 29, 185, 18, 150, 22, 188, 72, 128, 84, 96, 47, 192, 126, 56, 163, 50, 157, 165, 97, 166, 180, 7, 46, 30, 191, 124, 5, 48, 175, 68, 36, 89, 177, 11, 176, 183, 99, 90, 55, 26, 10, 58, 115, 155, 179, 156]
16. Length 201
[23, 8, 58, 24, 19, 87, 98, 187, 17, 130, 116, 141, 129, 166, 29, 191, 81, 105, 137, 171, 39, 67, 46, 150, 102, 26, 163, 183, 170, 72, 160, 43, 9, 197, 189, 173, 196, 68, 100, 16, 93, 175, 74, 28, 133, 122, 27, 79, 107, 162, 62, 192, 108, 104, 97, 12, 60, 155, 161, 82, 167, 158, 149, 30, 124, 22, 168, 115, 134, 94, 34, 184, 127, 121, 177, 112, 142, 95, 164, 41, 59, 55, 143, 85, 176, 3, 156, 148, 153, 42, 180, 145, 78, 147, 119, 109, 139, 178, 61, 181, 136, 157, 91, 84, 47, 71, 70, 118, 18, 63, 80, 56, 123, 194, 117, 195, 152, 66, 48, 11, 99, 201, 128, 151, 138, 64, 21, 131, 159, 103, 75, 49, 169, 113, 53, 114, 69, 54, 165, 38, 101, 76, 200, 199, 140, 125, 193, 88, 32, 51, 126, 14, 13, 77, 52, 50, 198, 172, 5, 92, 96, 15, 106, 182, 31, 83, 120, 57, 135, 65, 7, 154, 20, 25, 45, 1, 6, 73, 40, 174, 132, 10, 111, 186, 190, 4, 36, 188, 185, 146, 44, 110, 179, 2, 90, 86, 35, 37, 33, 89, 144]
17. Length 201
[97, 146, 168, 5, 56, 147, 189, 92, 154, 13, 185, 109, 45, 126, 17, 10, 53, 98, 88, 41, 163, 99, 157, 35, 125, 34, 173, 171, 138, 104, 149, 172, 60, 183, 36, 65, 32, 180, 87, 167, 59, 84, 188, 11, 69, 57, 174, 61, 66, 7, 8, 111, 91, 58, 128, 94, 141, 139, 31, 78, 156, 70, 16, 162, 26, 33, 106, 175, 103, 21, 164, 110, 159, 80, 200, 82, 123, 144, 44, 148, 4, 55, 179, 184, 186, 124, 63, 107, 54, 112, 137, 165, 121, 25, 132, 196, 90, 89, 71, 160, 95, 117, 197, 37, 108, 39, 115, 12, 52, 119, 120, 79, 29, 49, 93, 22, 122, 161, 76, 38, 72, 169, 85, 178, 77, 105, 190, 100, 9, 86, 177, 194, 2, 136, 114, 51, 68, 19, 47, 195, 113, 193, 67, 96, 182, 170, 50, 83, 143, 166, 3, 192, 24, 127, 140, 176, 134, 158, 116, 199, 1, 135, 118, 145, 14, 15, 155, 48, 42, 73, 46, 102, 191, 28, 201, 181, 75, 133, 153, 6, 131, 130, 81, 20, 198, 64, 142, 150, 27, 101, 18, 30, 40, 23, 129, 43, 62, 187, 152, 151, 74]
18. Length 205
[161, 197, 177, 118, 94, 112, 13, 190, 200, 166, 127, 80, 115, 204, 186, 60, 50, 97, 175, 32, 26, 65, 16, 4, 55, 120, 143, 187, 121, 29, 18, 82, 17, 21, 144, 20, 88, 195, 99, 67, 203, 23, 176, 126, 137, 77, 70, 30, 103, 182, 113, 119, 36, 47, 90, 98, 54, 3, 49, 105, 57, 135, 153, 142, 174, 155, 158, 11, 157, 22, 171, 110, 28, 196, 129, 163, 79, 63, 38, 145, 140, 2, 128, 180, 106, 59, 25, 184, 81, 164, 95, 39, 68, 78, 178, 156, 72, 51, 202, 66, 48, 101, 71, 108, 130, 5, 107, 147, 199, 12, 27, 150, 167, 91, 64, 170, 191, 151, 149, 168, 34, 125, 188, 181, 139, 58, 75, 189, 124, 152, 183, 7, 111, 89, 84, 52, 141, 83, 69, 62, 73, 43, 123, 14, 179, 162, 114, 138, 117, 159, 74, 85, 10, 96, 86, 31, 132, 1, 104, 109, 45, 165, 148, 172, 154, 92, 173, 40, 19, 56, 37, 205, 44, 193, 122, 185, 93, 133, 53, 9, 169, 6, 61, 136, 46, 76, 33, 15, 116, 198, 160, 194, 131, 41, 42, 35, 146, 134, 192, 8, 87, 201, 100, 24, 102]
19. Length 211
[200, 36, 204, 198, 190, 161, 57, 108, 180, 203, 135, 48, 134, 47, 158, 10, 41, 11, 23, 127, 167, 121, 109, 211, 201, 1, 42, 40, 86, 104, 147, 139, 145, 101, 144, 166, 176, 92, 118, 54, 182, 30, 58, 123, 124, 67, 125, 154, 187, 168, 103, 17, 72, 98, 12, 184, 59, 87, 174, 93, 45, 116, 73, 69, 74, 80, 56, 14, 34, 85, 38, 185, 165, 110, 164, 151, 43, 192, 62, 4, 140, 170, 197, 111, 173, 141, 65, 77, 70, 136, 206, 83, 100, 148, 25, 183, 209, 189, 150, 33, 46, 16, 64, 114, 71, 102, 91, 39, 177, 196, 169, 128, 129, 44, 75, 188, 146, 26, 84, 138, 162, 194, 105, 37, 35, 88, 156, 130, 193, 19, 179, 82, 106, 181, 153, 28, 53, 21, 195, 66, 159, 115, 113, 112, 191, 172, 63, 143, 178, 94, 160, 186, 31, 29, 90, 68, 205, 155, 119, 117, 157, 107, 60, 79, 171, 149, 6, 24, 27, 50, 51, 126, 15, 133, 2, 131, 7, 49, 207, 163, 18, 120, 199, 61, 52, 32, 208, 20, 210, 13, 78, 55, 137, 202, 152, 8, 81, 76, 9, 97, 22, 99, 132, 95, 122, 89, 175, 5, 3, 96, 142]
20. Length 226
[204, 79, 88, 98, 197, 32, 40, 117, 153, 167, 29, 74, 170, 115, 127, 210, 22, 109, 65, 47, 41, 132, 110, 158, 192, 99, 96, 224, 190, 143, 33, 225, 195, 19, 70, 73, 54, 161, 75, 179, 181, 207, 26, 221, 66, 130, 152, 131, 30, 35, 155, 69, 68, 38, 129, 95, 116, 214, 7, 186, 62, 27, 212, 125, 216, 86, 148, 164, 141, 4, 140, 222, 16, 46, 12, 215, 78, 219, 211, 134, 118, 171, 121, 52, 123, 56, 220, 15, 25, 100, 137, 163, 51, 91, 10, 83, 55, 187, 182, 201, 149, 160, 8, 14, 218, 77, 3, 184, 114, 43, 122, 135, 142, 104, 120, 198, 45, 108, 85, 189, 151, 175, 136, 165, 226, 97, 124, 200, 60, 172, 20, 67, 1, 174, 87, 102, 119, 188, 223, 199, 103, 89, 49, 213, 57, 9, 101, 112, 36, 176, 194, 92, 145, 180, 168, 111, 94, 178, 39, 166, 193, 17, 2, 154, 58, 156, 217, 13, 80, 202, 206, 169, 107, 177, 144, 205, 139, 93, 34, 64, 106, 150, 146, 126, 185, 208, 63, 203, 105, 18, 191, 53, 183, 209, 6, 23, 84, 5, 61, 59, 162, 128, 37, 50, 28, 159, 173, 196, 24, 31, 72, 138, 82, 48, 133, 147, 42, 113, 81, 90, 71, 21, 11, 157, 76, 44]
21. Length 227
[197, 52, 91, 42, 29, 113, 82, 68, 147, 225, 80, 167, 117, 142, 140, 216, 65, 195, 97, 61, 133, 209, 214, 58, 152, 71, 56, 182, 201, 163, 227, 186, 63, 171, 207, 102, 161, 136, 224, 146, 92, 175, 45, 217, 6, 99, 20, 119, 210, 93, 77, 211, 21, 70, 90, 96, 115, 100, 183, 173, 69, 98, 172, 75, 111, 203, 19, 129, 35, 155, 74, 37, 23, 51, 192, 212, 33, 64, 59, 194, 112, 135, 1, 184, 5, 166, 185, 84, 199, 138, 144, 86, 128, 26, 190, 73, 179, 27, 118, 223, 46, 95, 159, 153, 226, 25, 180, 132, 189, 60, 32, 208, 123, 89, 87, 22, 181, 143, 47, 18, 198, 219, 156, 148, 193, 122, 110, 28, 106, 39, 30, 103, 4, 176, 114, 3, 131, 107, 204, 218, 141, 169, 16, 206, 36, 188, 174, 54, 94, 50, 205, 104, 170, 160, 72, 165, 78, 24, 222, 8, 108, 81, 76, 15, 13, 126, 79, 7, 105, 125, 162, 83, 41, 145, 139, 66, 127, 38, 12, 187, 130, 221, 48, 164, 191, 157, 88, 168, 196, 10, 9, 53, 124, 150, 31, 116, 49, 34, 200, 134, 220, 121, 2, 62, 149, 158, 101, 17, 202, 11, 109, 85, 55, 67, 120, 43, 154, 44, 215, 177, 178, 40, 57, 14, 213, 151, 137]
22. Length 230
[69, 204, 215, 61, 97, 149, 9, 11, 137, 71, 37, 219, 92, 115, 156, 159, 200, 222, 3, 89, 172, 177, 203, 45, 54, 82, 147, 176, 168, 6, 26, 81, 25, 132, 212, 70, 228, 122, 225, 141, 100, 12, 124, 30, 146, 73, 19, 49, 52, 62, 217, 166, 191, 102, 163, 50, 181, 7, 134, 58, 76, 199, 179, 169, 197, 108, 174, 22, 186, 171, 114, 103, 173, 68, 65, 4, 13, 117, 64, 10, 126, 77, 206, 133, 121, 60, 40, 38, 59, 178, 224, 211, 187, 80, 220, 140, 8, 34, 130, 41, 95, 105, 227, 66, 210, 180, 192, 106, 209, 107, 157, 188, 170, 101, 131, 87, 14, 165, 78, 182, 136, 193, 190, 20, 67, 125, 36, 5, 145, 218, 99, 138, 154, 16, 29, 152, 194, 53, 148, 93, 202, 229, 198, 109, 43, 214, 150, 51, 128, 216, 1, 83, 196, 135, 74, 119, 75, 42, 142, 72, 226, 185, 116, 162, 63, 2, 112, 33, 184, 158, 15, 213, 144, 223, 98, 57, 160, 143, 90, 44, 205, 35, 21, 48, 151, 85, 123, 32, 47, 39, 189, 161, 56, 207, 84, 94, 230, 46, 164, 113, 175, 18, 195, 110, 127, 96, 129, 88, 17, 153, 104, 91, 86, 31, 118, 111, 120, 201, 28, 221, 23, 139, 24, 27, 167, 208, 183, 155, 79, 55]
23. Length 238
[202, 18, 122, 135, 11, 57, 103, 35, 86, 2, 84, 232, 208, 186, 54, 77, 145, 101, 105, 137, 210, 234, 207, 93, 55, 63, 230, 66, 160, 10, 223, 36, 34, 216, 104, 174, 121, 25, 166, 75, 167, 176, 61, 32, 118, 89, 68, 5, 14, 27, 204, 99, 149, 88, 91, 222, 37, 144, 108, 78, 128, 131, 190, 17, 65, 168, 225, 165, 41, 49, 38, 72, 43, 147, 158, 74, 130, 7, 82, 64, 97, 69, 100, 22, 152, 85, 48, 33, 218, 47, 228, 113, 40, 185, 219, 112, 180, 120, 4, 213, 179, 194, 51, 96, 221, 44, 238, 31, 117, 114, 229, 81, 164, 193, 236, 26, 59, 30, 151, 12, 115, 170, 24, 70, 227, 159, 133, 52, 134, 203, 15, 197, 155, 83, 50, 111, 195, 139, 109, 127, 188, 87, 62, 157, 226, 142, 98, 76, 211, 138, 58, 140, 198, 220, 16, 46, 183, 107, 106, 29, 163, 173, 209, 217, 215, 1, 177, 233, 199, 110, 172, 23, 212, 79, 94, 102, 39, 20, 178, 150, 175, 119, 8, 13, 42, 156, 201, 73, 200, 124, 53, 161, 92, 123, 224, 143, 196, 28, 9, 6, 80, 56, 148, 125, 214, 60, 171, 153, 231, 181, 205, 19, 95, 206, 154, 132, 169, 116, 3, 126, 187, 162, 191, 67, 136, 45, 192, 189, 235, 129, 21, 141, 237, 184, 90, 146, 182, 71]
24. Length 241
[2, 33, 49, 83, 207, 204, 13, 57, 115, 86, 102, 219, 232, 44, 177, 197, 171, 227, 191, 10, 25, 162, 62, 11, 76, 214, 163, 201, 130, 91, 233, 194, 112, 179, 66, 139, 183, 116, 196, 193, 150, 211, 30, 144, 209, 97, 174, 3, 68, 38, 120, 165, 56, 64, 87, 15, 79, 131, 206, 96, 188, 7, 99, 195, 129, 8, 186, 78, 212, 125, 161, 230, 225, 239, 47, 107, 53, 218, 164, 106, 198, 215, 181, 226, 6, 175, 167, 236, 67, 80, 210, 128, 155, 40, 63, 74, 113, 89, 18, 190, 124, 221, 59, 149, 103, 42, 156, 157, 200, 168, 34, 77, 65, 146, 5, 187, 222, 231, 140, 141, 172, 234, 100, 94, 132, 237, 24, 216, 152, 22, 51, 69, 35, 43, 105, 23, 61, 1, 72, 135, 104, 9, 12, 21, 46, 192, 159, 205, 158, 109, 28, 98, 50, 122, 111, 71, 166, 229, 37, 114, 173, 134, 136, 81, 121, 185, 118, 223, 20, 14, 108, 82, 178, 54, 26, 153, 36, 39, 117, 147, 95, 90, 16, 17, 170, 119, 199, 19, 84, 213, 88, 93, 151, 4, 101, 142, 110, 184, 55, 138, 75, 133, 148, 145, 45, 70, 217, 143, 224, 241, 31, 240, 182, 52, 238, 126, 85, 154, 137, 160, 27, 180, 60, 29, 32, 169, 235, 123, 176, 48, 220, 203, 228, 127, 41, 58, 73, 92, 189, 202, 208]
25. Length 241
[105, 160, 132, 32, 10, 117, 76, 2, 190, 108, 178, 51, 71, 237, 232, 47, 14, 124, 100, 31, 169, 196, 8, 184, 21, 151, 223, 86, 42, 127, 55, 58, 229, 4, 219, 46, 238, 179, 24, 194, 203, 122, 66, 15, 81, 146, 172, 106, 129, 135, 216, 120, 92, 231, 144, 195, 181, 162, 69, 45, 137, 136, 9, 30, 5, 188, 91, 49, 147, 233, 198, 17, 241, 163, 36, 18, 183, 59, 16, 29, 116, 182, 41, 48, 23, 39, 154, 210, 68, 167, 95, 213, 79, 225, 37, 157, 109, 143, 78, 142, 173, 155, 200, 110, 20, 73, 141, 168, 156, 126, 150, 201, 114, 1, 230, 211, 217, 131, 140, 204, 209, 149, 103, 199, 165, 175, 35, 107, 74, 63, 193, 239, 218, 234, 197, 224, 174, 121, 60, 88, 22, 171, 133, 207, 152, 34, 43, 228, 125, 115, 101, 7, 12, 220, 82, 153, 134, 52, 130, 70, 72, 44, 177, 89, 65, 98, 94, 53, 208, 227, 161, 3, 123, 236, 221, 87, 102, 50, 90, 180, 185, 186, 67, 77, 26, 212, 27, 222, 6, 145, 11, 13, 84, 25, 164, 64, 85, 139, 214, 189, 61, 96, 191, 128, 93, 138, 148, 19, 119, 202, 75, 176, 159, 56, 104, 206, 40, 187, 215, 62, 166, 240, 112, 226, 170, 83, 97, 57, 99, 38, 28, 113, 205, 158, 235, 111, 54, 192, 118, 80, 33]
26. Length 244
[89, 13, 154, 161, 235, 225, 92, 188, 215, 194, 54, 58, 128, 21, 165, 85, 144, 205, 142, 77, 109, 24, 83, 69, 72, 7, 224, 240, 191, 204, 183, 203, 68, 70, 63, 95, 206, 170, 153, 180, 45, 178, 35, 27, 190, 132, 222, 41, 40, 156, 97, 20, 217, 177, 167, 65, 23, 136, 216, 234, 38, 201, 236, 164, 82, 241, 10, 141, 148, 229, 5, 125, 113, 159, 193, 187, 130, 179, 52, 108, 86, 196, 174, 123, 56, 116, 227, 30, 239, 98, 186, 67, 135, 118, 163, 43, 32, 50, 231, 226, 232, 172, 200, 99, 6, 143, 39, 93, 107, 34, 129, 157, 100, 127, 15, 84, 81, 73, 121, 220, 44, 8, 57, 105, 91, 171, 162, 211, 244, 104, 112, 238, 212, 133, 71, 192, 145, 160, 87, 181, 60, 184, 119, 4, 55, 96, 53, 12, 213, 124, 94, 22, 42, 3, 48, 131, 117, 140, 138, 228, 219, 155, 59, 29, 202, 169, 114, 101, 47, 233, 176, 139, 207, 33, 79, 16, 51, 66, 75, 90, 198, 168, 166, 31, 151, 49, 208, 150, 111, 14, 25, 197, 17, 76, 80, 78, 9, 173, 26, 137, 19, 120, 199, 106, 152, 88, 147, 36, 158, 28, 243, 221, 110, 74, 175, 237, 61, 2, 62, 214, 189, 134, 195, 218, 18, 102, 46, 103, 11, 122, 146, 185, 182, 209, 1, 149, 115, 64, 37, 126, 230, 223, 242, 210]
27. Length 246
[28, 186, 214, 18, 220, 73, 20, 88, 234, 187, 27, 102, 22, 129, 10, 228, 196, 56, 47, 2, 16, 67, 124, 137, 177, 179, 223, 147, 188, 23, 103, 109, 149, 60, 229, 99, 222, 90, 49, 80, 158, 93, 171, 71, 175, 143, 19, 212, 40, 226, 219, 120, 146, 66, 167, 232, 94, 174, 237, 9, 173, 70, 122, 241, 58, 82, 191, 211, 180, 104, 53, 36, 83, 37, 131, 25, 162, 32, 210, 144, 145, 69, 135, 63, 154, 165, 46, 57, 50, 74, 128, 140, 112, 118, 125, 231, 221, 233, 95, 200, 153, 6, 166, 98, 208, 91, 89, 141, 4, 26, 134, 86, 8, 30, 157, 156, 224, 201, 243, 7, 161, 1, 84, 115, 44, 230, 78, 79, 5, 17, 194, 148, 152, 121, 193, 107, 240, 181, 29, 43, 65, 164, 45, 110, 64, 195, 216, 127, 59, 197, 178, 151, 139, 85, 75, 11, 204, 184, 77, 54, 51, 205, 108, 142, 130, 138, 238, 87, 38, 101, 96, 31, 215, 244, 242, 172, 213, 136, 97, 35, 39, 76, 42, 245, 123, 227, 24, 168, 33, 159, 217, 239, 55, 176, 68, 207, 106, 132, 15, 116, 61, 198, 62, 182, 225, 202, 105, 150, 183, 81, 170, 13, 41, 199, 3, 185, 235, 14, 155, 21, 126, 119, 169, 72, 12, 236, 48, 209, 190, 113, 218, 100, 52, 111, 189, 92, 192, 114, 117, 160, 133, 203, 163, 34, 206, 246]
28. Length 250
[119, 57, 59, 181, 212, 120, 236, 121, 99, 247, 138, 187, 175, 108, 107, 197, 123, 101, 141, 77, 201, 3, 52, 60, 56, 240, 157, 39, 42, 199, 23, 18, 136, 74, 137, 143, 229, 170, 20, 160, 206, 219, 191, 185, 46, 223, 150, 190, 116, 96, 198, 221, 220, 159, 238, 48, 176, 113, 168, 33, 44, 142, 67, 244, 13, 218, 122, 246, 214, 234, 237, 27, 165, 24, 153, 90, 84, 154, 235, 196, 80, 111, 102, 231, 228, 135, 16, 148, 26, 45, 10, 71, 156, 224, 183, 232, 72, 94, 132, 54, 58, 248, 144, 213, 139, 129, 245, 115, 25, 164, 87, 19, 193, 81, 32, 78, 91, 167, 171, 40, 92, 226, 109, 69, 86, 38, 61, 5, 14, 118, 145, 103, 53, 93, 172, 178, 225, 68, 163, 210, 179, 192, 208, 169, 17, 12, 50, 233, 6, 55, 243, 158, 88, 188, 242, 36, 173, 126, 155, 184, 216, 149, 47, 76, 200, 1, 112, 28, 161, 174, 41, 73, 222, 66, 37, 63, 64, 124, 89, 205, 9, 186, 202, 70, 203, 127, 105, 250, 182, 79, 43, 133, 8, 241, 114, 128, 51, 83, 98, 49, 209, 7, 95, 151, 162, 189, 180, 75, 195, 62, 207, 21, 104, 30, 117, 110, 140, 29, 227, 249, 82, 152, 11, 34, 85, 106, 217, 211, 2, 35, 215, 4, 230, 134, 31, 194, 97, 22, 125, 130, 100, 239, 131, 166, 65, 15, 146, 177, 204, 147]
29. Length 253
[46, 245, 174, 180, 85, 29, 141, 70, 252, 119, 214, 225, 86, 91, 41, 67, 219, 118, 127, 243, 2, 71, 157, 114, 55, 92, 5, 200, 199, 139, 191, 235, 153, 102, 206, 171, 117, 58, 223, 249, 11, 211, 202, 175, 156, 133, 57, 163, 47, 65, 213, 247, 189, 111, 177, 49, 124, 154, 164, 145, 80, 15, 232, 142, 39, 69, 201, 185, 229, 215, 170, 42, 3, 248, 169, 136, 149, 218, 237, 90, 135, 7, 242, 246, 23, 186, 31, 4, 167, 207, 173, 132, 195, 196, 78, 212, 22, 35, 194, 54, 184, 183, 222, 230, 88, 43, 144, 151, 34, 97, 6, 109, 37, 147, 72, 158, 134, 33, 51, 238, 165, 162, 9, 63, 166, 113, 137, 198, 50, 121, 106, 224, 19, 104, 95, 129, 193, 79, 192, 122, 30, 12, 234, 168, 76, 103, 73, 66, 188, 178, 172, 176, 250, 182, 110, 231, 155, 26, 197, 10, 152, 98, 131, 25, 36, 81, 138, 150, 227, 24, 112, 120, 204, 75, 8, 179, 94, 17, 140, 32, 77, 61, 233, 38, 205, 93, 99, 27, 208, 56, 216, 48, 241, 20, 130, 240, 115, 83, 60, 108, 28, 13, 89, 128, 160, 82, 40, 126, 16, 253, 21, 251, 228, 59, 159, 64, 203, 236, 52, 18, 181, 105, 107, 239, 220, 44, 74, 125, 209, 84, 226, 217, 210, 190, 101, 100, 68, 116, 161, 148, 244, 221, 96, 45, 123, 187, 62, 87, 53, 1, 146, 143, 14]
30. Length 256
[159, 248, 75, 43, 111, 38, 4, 17, 155, 87, 81, 208, 53, 230, 65, 11, 108, 228, 146, 212, 137, 225, 144, 189, 86, 105, 84, 128, 97, 50, 223, 15, 83, 169, 217, 47, 88, 236, 114, 181, 115, 177, 102, 250, 246, 104, 80, 45, 240, 14, 196, 52, 247, 41, 198, 32, 182, 206, 226, 101, 70, 94, 113, 49, 254, 59, 42, 154, 77, 253, 112, 215, 99, 25, 134, 92, 95, 150, 64, 178, 118, 79, 130, 63, 129, 131, 57, 218, 85, 204, 3, 163, 158, 186, 10, 199, 24, 125, 251, 51, 74, 160, 207, 120, 233, 30, 19, 9, 56, 167, 58, 117, 164, 54, 220, 229, 234, 203, 211, 103, 205, 69, 39, 5, 31, 191, 106, 180, 116, 245, 21, 222, 91, 235, 8, 2, 214, 29, 238, 176, 135, 61, 227, 202, 122, 252, 231, 89, 187, 37, 149, 96, 190, 172, 73, 18, 71, 1, 179, 46, 156, 201, 165, 256, 151, 27, 242, 188, 126, 124, 244, 100, 107, 143, 170, 72, 255, 40, 67, 192, 185, 219, 20, 157, 98, 237, 136, 168, 141, 224, 232, 44, 139, 132, 22, 60, 109, 90, 175, 171, 62, 23, 161, 12, 76, 210, 68, 184, 93, 243, 48, 209, 174, 200, 121, 123, 36, 173, 140, 133, 145, 6, 110, 152, 142, 241, 55, 138, 147, 193, 213, 127, 7, 34, 66, 153, 26, 13, 162, 183, 239, 78, 249, 221, 28, 194, 16, 35, 33, 82, 195, 148, 216, 119, 166, 197]

Python 3 (avec PyPy) - score: 607771

Edit: Je pense que le bug est corrigé, mais je ne suis toujours pas convaincu que cela fonctionne jusqu'à ce que je le prouve

def d(a, b, N):
    a, b = a%N, b%N

    if a >= b:
        return a-b
    else:
        return a+(N-b)

def gt(a, b, N):
    if a == N and b == 1:
        return False
    if a == 1 and b == N:
        return True
    return a > b

def solve(numbers):
    N = len(numbers)
    best_move = None
    target = sorted(numbers)

    if N == 2:
      return "" if numbers == [1,2] else "P"

    for b in range(N):
        nums = numbers[:]
        moves = []
        head_ptr = 0 # Which element should be at the start of the list if we actually moved stuff
        reference = target[b:]+target[:b]
        ref_d = {t:i for i,t in enumerate(reference)}

        while True:
            for pops in range(N):
                ptr = (head_ptr + pops) % N

                # Magic
                d1 = d(ref_d[nums[ptr-1]],ptr-1,N)+d(ptr,ref_d[nums[ptr]],N)
                d2 = d(ref_d[nums[ptr]],ptr,N)+d(ptr-1,ref_d[nums[ptr-1]],N)

                if d1 > d2 or (d1 == d2 and gt(nums[ptr-1], nums[ptr], N)):
                    moves.append("P"*pops + "S")
                    head_ptr = (head_ptr + pops) % N
                    nums[ptr-1],nums[ptr] = nums[ptr],nums[ptr-1]
                    break

            else:
                if nums[nums.index(1):]+nums[:nums.index(1)] != target:
                    print("This algorithm is seriously broken.\n")
                moves.append("P"*((N+nums.index(1)-head_ptr)%N))
                break

        moves = "".join(moves)

        if not best_move or len(moves) < len(best_move):
            best_move = moves

    return best_move

Usage

solve([3, 4, 2, 1, 5])

Explication

Le programme effectue simplement des swaps de tri à bulles, en utilisant l'observation que:
S: n 1 2 3 ... n-1 0 PS: 0 2 3 ... n-1 n 1 PPS: 1 3 ... n-1 n 0 2 PPPS: 2 ... n-1 n 0 1 3 ...

En d'autres termes, les ipoussées suivies d'un swap signifient que l'élément iest échangé avec l'élément i-1, l'index enveloppant. Cependant, nous devons garder une trace du fait que la liste est décalée ce faisant.

Pour faire mieux que le type de bulle habituel, nous essayons d'appliquer une heuristique afin de nous assurer que nous n'effectuons pas trop de swaps inutiles, en veillant à ce que tout swap rapproche les deux éléments de leurs objectifs respectifs (je n'ai pas formellement prouvé c'est correct, mais cela semble fonctionner jusqu'à présent). Nous prenons ensuite la meilleure solution parmi de nombreuses configurations (CPython prend un certain temps, mais PyPy fait ce travail relativement rapidement).

Notation

Sortie sur Pastebin.

Précédent tri de bulles naïves ver. (note: 1126232)

Celui-ci fonctionne définitivement.

def cyclic_sorted(nums):
    for i in range(len(nums)):
        if nums[i:] + nums[:i] == sorted(nums):
            return i
    return False

def solve(nums):
    N = len(nums)

    def gt(a, b):
        if a == 1 and b == N:
            return True
        if a == N and b == 1:
            return False
        return a > b

    moves = []
    head_ptr = 0 # Which element should be at the start of the list if we actually moved stuff

    while nums != sorted(nums):
        pops = 0
        ptr_offset = 0

        while pops < N:
            ptr = (head_ptr + pops) % N

            if (not moves or pops > 0) and gt(nums[ptr-1], nums[ptr]):
                moves.append("P"*pops + "S")
                head_ptr = (head_ptr + pops) % N

                nums[ptr-1],nums[ptr] = nums[ptr],nums[ptr-1]
                break

            pops += 1

        else:
            moves.append("P"*cyclic_sorted(nums[head_ptr:]+nums[:head_ptr]))
            break

    return "".join(moves)

Javascript ES6 - 607 771

function popsort( iData ) {
    var sSP, iLen,
        sSP_Opt = popsortimpl( iData.slice( 0 ), 0 ),
        iOptLen = sSP_Opt.length;

    for( var n = iData.length, i = 2; i <= n; i++ )
        if( (iLen = (sSP = popsortimpl( iData.slice( 0 ), i - 1 )).length) < iOptLen ) {
            iOptLen = iLen;
            sSP_Opt = sSP;
        }

    return sSP_Opt;
}

function popsortimpl( iData, iPivIdx ) {
    function issorted()
        { return iData.every( (_,i_) => _ == i_+1 ); }

    function swap() {
        var i_ = iData[0];

        iData[0] = iData[n-1];
        iData[n-1] = i_;

        sSP.push( 'S' );
    }

    function pop() {
        iData.push( iData.shift() );
        if( --iPivIdx < 0 )
            iPivIdx += n;

        sSP.push( 'P' );
    }

    function dist2home( iIdx_, i_ ) {
        var iHome_ = (iPivIdx + i_) %n,
            iDist1_ = iIdx_ - iHome_,
            iDist2_ = iHome_ - iIdx_;

        if( iDist1_ < 0 )
            iDist1_ += n;
        if( iDist2_ < 0 )
            iDist2_ += n;

        return Math.min( iDist1_, iDist2_*Math.max( 1, n/50 ) );
    }

    var n = iData.length,
        sSP = [];

    while( !issorted() ) {
        var iDistP = Math.max( dist2home( 0, iData[0] ), dist2home( n - 1, iData[n - 1] ) ),
            iDistS = Math.max( dist2home( n - 1, iData[0] ), dist2home( 0, iData[n - 1] ) );

        if( iDistS < iDistP )
            swap();
        else pop();
    }
    return sSP.join('');
}

Implémente un tri de bulles "à l'extrémité la plus proche" qui fait bouillir les éléments vers le haut ou vers le bas selon l'itinéraire le plus court (bulle vers le haut ou bulle vers le bas) vers une position de référence.

Je ne crois pas que la routine soit optimale, mais elle devrait être raisonnablement proche d'elle. En prime, il exécute l'ensemble complet des vecteurs de test en millisecondes.

Mis à jour à pour itérer sur le point pivot afin d'améliorer la compétitivité. J'ai également introduit une heuristique pour compenser le fait que les éléments ont une mobilité plus faible se déplaçant "vers le haut" de la liste que se déplaçant "vers le bas" (un phénomène analogue à la différence de mobilité des électrons et des trous dans un semi-conducteur). Il existe des différences majeures entre cette implémentation et les Sp3000, d'où le fait que les deux marquent exactement 607 771 est effrayant. Halloween effrayant.

La routine dure maintenant environ 20 secondes.

Exemple de sortie

popsort( [2, 7, 5, 3, 4, 6, 1] )

les rendements

PSPPSPSPPPS

OCaml, score: 1136707 1136599

Edit: j'ai foiré! J'avais lu Sque j'échangerais les éléments adjacents et j'ai manqué que les premier et dernier éléments soient échangés. Cette implémentation s'appuie sur cela, comme il ressort de l' evalimplémentation. Edit²: je l'ai corrigé en utilisant l'observation que vous pouvez écrire ce que je pensais être SP en tant que P S.

Le temps d'exécution est de 1,33 18 1,01 secondes sur mon système en utilisant l' interpréteur compilé binaire.

type sp = S | P

let string_of_sp = function
  | S -> "S"
  | P -> "P"

let rec eval (e : sp list) (xs : int list) : int list =
  match e, xs with
  | [], xs -> xs
  | P :: S :: e, x1 :: x2 :: xs -> eval e (x1 :: xs @ [x2])
  | P :: e, x :: xs -> eval e (xs @ [x])
  | _ -> assert false

let generate_sp_sequence xs : sp list =
  let sorted = List.sort compare xs in
  let rec generate_sp_sequence ((xs, ys) : int list * int list) acc : sp list =
    if sorted = ys @ List.rev xs
    then acc
    else 
      match ys with
      | v1 :: v2 :: ys' ->
         if v1 > v2
         then generate_sp_sequence (v2 :: xs, v1 :: ys') (S :: P :: acc)
         else generate_sp_sequence (v1 :: xs, v2 :: ys') (P :: acc)
      | [x] ->
         let ys = List.rev (x :: xs) in
         generate_sp_sequence ([], ys) (P :: acc)
      | [] ->
         assert false
  in List.rev @@ generate_sp_sequence ([], xs) []


(** Uncomment to run tests **)
(*
let test =
  QCheck.(mk_test
            ~n:1000
            ~name:"generate_sp_sequence sorting test"
            ~pp:PP.(list int)
            Arbitrary.(list ~start:2 ~stop:256 small_int)
            (fun xs ->
             Prop.assume (List.length xs >= 2);
             eval (generate_sp_sequence ([], xs))
                  xs
             = List.sort compare xs))

let _ = QCheck.run test
 *)

let score_test = ... (* not included for brevity *)

let score =
  List.map (fun xs -> generate_sp_sequence ([], xs)) score_test
  |> List.map List.length
  |> List.fold_left (+) 0

let _ =
  print_string "The score is: ";
  print_int score;
  print_newline ()

generate_sp_sequence exécute simplement bubbleort et génère les étapes en termes de S et P. Il peut générer des étapes inutiles.

C, score: 607771

Il s'avère que ma solution est très similaire à la solution Python de Sp3000 (ce qui explique le score identique). Je n'ai jamais utilisé Python donc je ne peux pas le dire avec certitude, mais je pense que le concept est exactement le même:

Pour chaque nombre r dans 0..n-1, fixez un objectif d'un tableau trié tourné r fois à partir de la position initiale (c'est-à-dire contenant P pops avec r = P mod n), et trouvez une série de mouvements résultant de cette configuration. Enregistrez la séquence de mouvements la plus courte pour tout r.
N'effectuez des swaps que lorsque le swap rapproche l'élément le plus éloigné de sa position cible (en regardant dans les deux sens), ou lorsque le swap rapproche les deux éléments si les deux sont également éloignés.

Code

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* Returns true if the array is sorted starting at position 'offset' */
int is_sorted(int *array, int n, int offset)
{
    int i;
    for (i = 0; i < n && array[(offset+i)%n] == i+1; i++);
    return i == n;
}

/* Find moves that would sort the array, assuming the first element will
   be at position (offset + n/2) % n */
int get_moves(int *array, int n, int offset, int stop_after, char *moves)
{
    int tmp, posA = n-1, posB = 0, counter = 0;
    /* Repeat until sorted or reaching the maximum number of moves (previous
       best, or the worst case upper bound if no previous solution) */
    for (; counter < stop_after && !is_sorted(array, n, posB); posA = (posA+1)%n, posB = (posB+1)%n, moves[counter++] = 'P')
    {
        /* Perform a swap if it would move whichever element is further away
           closer to its target */
        if ((array[posA] - posA + offset + n) % n >
            (array[posB] - posB + offset + n) % n)
        {
            tmp = array[posA];
            array[posA] = array[posB];
            array[posB] = tmp;
            moves[counter++] = 'S';
            if (is_sorted(array, n, posB))
            {
                break;
            }
        }
    }
    return counter;
}

int *parse_input(int _argc, char **_argv)
{
    int i;
    int *array = NULL;
    if (_argc > 1)
    {
        array = malloc((_argc-1) * sizeof(int));
        _argv[1]++; /* remove initial square bracket */
        for (i = 1; i < _argc; i++)
        {
            array[i-1] = atoi(_argv[i]);
        }
    }
    return array;
}

int main(int _argc, char **_argv)
{
    int *orig_array = parse_input(_argc, _argv);
    if (orig_array != NULL)
    {
        int n = _argc - 1;
        /* Safe worst case upper bound representing n^2 "SP" moves */
        int worst_move_count = 2*n*n;

        int i, move_count, offset;
        int best_offset, best_move_count = worst_move_count;

        char *best_moves = malloc(worst_move_count + 1);
        char *moves = malloc(worst_move_count + 1);
        int *array = malloc(n * sizeof(int));

        memset(best_moves, 0, worst_move_count + 1);
        /* Try all offsets from 0 to n-1; i.e. find solutions for:
           1, 2, 3, ..., n-2, n-1, n
           2, 3, 4, ..., n-1, n,   1
           3, 4, 5, ..., n,   1,   2
           ...
           n, 1, 2, ..., n-3, n-2, n-1
        */
        for (offset = 0; offset < n; offset++)
        {
            memset(moves, 0, worst_move_count + 1);
            memcpy(array, orig_array, n*sizeof(int));
            move_count = get_moves(array, n, offset, best_move_count, moves);
            if (move_count < best_move_count)
            {
                strcpy(best_moves, moves);
                best_move_count = move_count;
                best_offset = offset;
            }
        }
        printf("%s\n", best_moves);

        free(best_moves);
        free(moves);
        free(array);
        free(orig_array);
    }
    return 0;
}

Usage

$ gcc -Ofast -o popswap popswap.c
$ ./popswap [2, 7, 5, 3, 4, 6, 1]
PSPPSPSPPPS
$ ./popswap [2, 7, 5, 3, 4, 6, 1]|tr -d '\n'|wc -c
11

Notation

Scénario:

#!/bin/sh
grep ^\\[ input.txt|while read line; do
    len=`echo $line|wc -w`;
    score=`./popswap $line|tr -d '\n'|wc -c`;
    echo "    $len $score";
done

Résultats:

$ ./scoring.sh |cut -d' ' -f 6|paste -sd+|bc
607771
$ time ./scoring.sh > /dev/null

real    0m1.926s
user    0m1.879s
sys     0m0.122s
$ ./scoring.sh
3 2
7 11
41 893
52 1546
65 2543
69 2686
75 3391
80 3728
103 6483
108 0
109 7103
151 14371
173 18663
177 19728
192 22824
201 24828
201 24752
205 25573
211 27509
226 32221
227 31928
230 33630
238 34603
241 36676
241 36505
244 37759
246 38106
250 38264
253 40040
256 41405

C ++ 11, score: 1122052

Implémentation très naïve qui ne prend pas en compte les trous dans la séquence d'entrée mais prend en compte la valeur minimale dans la séquence.

La liste d'arguments est juste la séquence de nombres, sans virgules ni crochets (par exemple: "./a.out 2 7 5")

#include <iostream>
#include <cstring>
#include <string>
using namespace std;

int* input  = 0;
int s_count = 0;
int p_count = 0;
int len;
int last;

void do_swap()
{
  int a = input[0];
  input[0] = input[last];
  input[last] = a;
  s_count++;
  cerr << "S";
}

void do_pop()
{
  int a = input[0];
  memmove(&input[0], &input[1], sizeof(int) * last);
  input[last] = a;
  p_count++;
  cerr << "P";
}

bool is_sorted()
{
  int i = 0;
  while (input[i] < input[i+1]) { if (++i == last) return true; }
  return false;
}

int main(int argc, char** args)
{
  int min_val = 256;

  len = argc - 1;
  last = len - 1;
  if (len <= 1)
    return 1;

  input = new int[len];
  for (int i = 2; i <= argc; i++)
  {
    int j = stoi(args[i-1]);
    input[i-2] = j;
    min_val = min(min_val, j);
  }

  while (!is_sorted())
  {
    if ((input[0]) == min_val)
      do_pop();
    else if (input[0] < input[last])
      do_swap();
    else if (input[0] > input[last])
      do_pop();
  }

  cerr << endl;
  cout << len << " " << (s_count + p_count) << endl;
  delete [] input;
  return 0;
}

Notation

3 2
7 19
41 1642
52 3236
65 4787
69 4966
75 6644
80 6090
103 12142
108 0
109 13774
151 24976
173 34061
177 37835
192 41994
201 48316
201 47276
205 49439
211 51551
226 58859
227 56824
230 58994
238 64227
241 65774
241 66287
244 71345
246 73426
250 71766
253 68629
256 77171