Heap sort
<source lang="java">
public static void heapsort(int n, double ra[]) { int l, j, ir, i; double rra;
l = (n >> 1) + 1; ir = n; for (;;) { if (l > 1) { rra = ra[--l]; } else { rra = ra[ir]; ra[ir] = ra[1]; if (--ir == 1) { ra[1] = rra; return; } } i = l; j = l << 1; while (j <= ir) { if (j < ir && ra[j] < ra[j + 1]) { ++j; } if (rra < ra[j]) { ra[i] = ra[j]; j += (i = j); } else { j = ir + 1; } } ra[i] = rra; } }
</source>