michael@0: /* The Great Computer Language Shootout
michael@0:    http://shootout.alioth.debian.org/
michael@0:    contributed by Isaac Gouy */
michael@0: 
michael@0: function fannkuch(n) {
michael@0:    var check = 0;
michael@0:    var perm = Array(n);
michael@0:    var perm1 = Array(n);
michael@0:    var count = Array(n);
michael@0:    var maxPerm = Array(n);
michael@0:    var maxFlipsCount = 0;
michael@0:    var m = n - 1;
michael@0: 
michael@0:    for (var i = 0; i < n; i++) perm1[i] = i;
michael@0:    var r = n;
michael@0: 
michael@0:    while (true) {
michael@0:       // write-out the first 30 permutations
michael@0:       if (check < 30){
michael@0:          var s = "";
michael@0:          for(var i=0; i<n; i++) s += (perm1[i]+1).toString();
michael@0:          check++;
michael@0:       }
michael@0: 
michael@0:       while (r != 1) { count[r - 1] = r; r--; }
michael@0:       if (!(perm1[0] == 0 || perm1[m] == m)) {
michael@0:          for (var i = 0; i < n; i++) perm[i] = perm1[i];
michael@0: 
michael@0:          var flipsCount = 0;
michael@0:          var k;
michael@0: 
michael@0:          while (!((k = perm[0]) == 0)) {
michael@0:             var k2 = (k + 1) >> 1;
michael@0:             for (var i = 0; i < k2; i++) {
michael@0:                var temp = perm[i]; perm[i] = perm[k - i]; perm[k - i] = temp;
michael@0:             }
michael@0:             flipsCount++;
michael@0:          }
michael@0: 
michael@0:          if (flipsCount > maxFlipsCount) {
michael@0:             maxFlipsCount = flipsCount;
michael@0:             for (var i = 0; i < n; i++) maxPerm[i] = perm1[i];
michael@0:          }
michael@0:       }
michael@0: 
michael@0:       while (true) {
michael@0:          if (r == n) return maxFlipsCount;
michael@0:          var perm0 = perm1[0];
michael@0:          var i = 0;
michael@0:          while (i < r) {
michael@0:             var j = i + 1;
michael@0:             perm1[i] = perm1[j];
michael@0:             i = j;
michael@0:          }
michael@0:          perm1[r] = perm0;
michael@0: 
michael@0:          count[r] = count[r] - 1;
michael@0:          if (count[r] > 0) break;
michael@0:          r++;
michael@0:       }
michael@0:    }
michael@0: }
michael@0: 
michael@0: var n = 8;
michael@0: var ret = fannkuch(n);
michael@0: assertEq(ret, 22)