1/* The Great Computer Language Shootout
2   http://shootout.alioth.debian.org/
3   contributed by Isaac Gouy */
4
5function fannkuch(n) {
6   var check = 0;
7   var perm = Array(n);
8   var perm1 = Array(n);
9   var count = Array(n);
10   var maxPerm = Array(n);
11   var maxFlipsCount = 0;
12   var m = n - 1;
13
14   for (var i = 0; i < n; i++) perm1[i] = i;
15   var r = n;
16
17   while (true) {
18      // write-out the first 30 permutations
19      if (check < 30){
20         var s = "";
21         for(var i=0; i<n; i++) s += (perm1[i]+1).toString();
22         check++;
23      }
24
25      while (r != 1) { count[r - 1] = r; r--; }
26      if (!(perm1[0] == 0 || perm1[m] == m)) {
27         for (var i = 0; i < n; i++) perm[i] = perm1[i];
28
29         var flipsCount = 0;
30         var k;
31
32         while (!((k = perm[0]) == 0)) {
33            var k2 = (k + 1) >> 1;
34            for (var i = 0; i < k2; i++) {
35               var temp = perm[i]; perm[i] = perm[k - i]; perm[k - i] = temp;
36            }
37            flipsCount++;
38         }
39
40         if (flipsCount > maxFlipsCount) {
41            maxFlipsCount = flipsCount;
42            for (var i = 0; i < n; i++) maxPerm[i] = perm1[i];
43         }
44      }
45
46      while (true) {
47         if (r == n) return maxFlipsCount;
48         var perm0 = perm1[0];
49         var i = 0;
50         while (i < r) {
51            var j = i + 1;
52            perm1[i] = perm1[j];
53            i = j;
54         }
55         perm1[r] = perm0;
56
57         count[r] = count[r] - 1;
58         if (count[r] > 0) break;
59         r++;
60      }
61   }
62}
63
64var n = 8;
65var ret = fannkuch(n);
66
67