void srt_bins_sort(int *h, int n, int cmp(int x, int y), int sgn)
  { int m;
    for (m = 1; m < n; m++)
      { /* Insert {h[m]} among {h[0..m-1]}: */
        int v = h[m], i = m;
        while ((i > 0) && (sgn*cmp(v, h[i-1]) < 0)) 
          { h[i] = h[i-1]; i--; }
        h[i] = v;
      }
  }