fannkuchredux benchmark implementation in dart

fannkuchredux.dart

#import('dart:core');

class FannkuchreduxTest {

  static int fannkuchredux(int n) {
      var perm = new List(n);
      var perm1  = new List(n);
      var count = new List(n);
      int maxFlipsCount = 0;
      int permCount = 0;
      int checksum = 0;
      int i;
      
      for (i = 0; i < n; i++) 
          perm1[i] = i;
      
      int r = n;
      
      while (true) {
          while  (r != 1) {
              count[r-1] = r;
              r -= 1;
          }

          for (i = 0; i < n; i += 1) 
              perm[i] = perm1[i];
          
          int flipsCount = 0;

          for (int k = perm[0]; k != 0; k = perm[0]) {
              int k2 = (k+1) >> 1;
              for (i = 0; i < k2; i++) {
                  int temp = perm[i];
                  perm[i] = perm[k-i];
                  perm[k-i] = temp;
              }
              flipsCount += 1;
          }
          
          if (flipsCount > maxFlipsCount) 
            maxFlipsCount = flipsCount; 
          
          int csi = flipsCount;
          if (permCount % 2 != 0) 
              csi = -flipsCount;
          checksum += csi;
          
          while (true) {
              if (r == n) {
                  print("$checksum");
                  return maxFlipsCount;
              }
          
              int perm0 = perm1[0];
              i = 0;
              while (i < r) {
                  int j = i + 1;
                  perm1[i] = perm1[j];
                  i = j;
              }
              perm1[r] = perm0;
              count[r] = count[r] - 1;
              if (count[r] > 0) 
                  break;
              r++;
          }
          permCount++;
      }    
      //return 0;
  }
}

void main() {
  int n = 11;
  int t1 =  Clock.now();
  int res = FannkuchreduxTest.fannkuchredux(n);
  print("Pfannkuchen($n) = $res\n");
  int t2 =  Clock.now();
  double t = (t2 - t1) / 1000;
  print("time: $t");
}