- /* Invariant: a[m..n-1] is a heap. */
- m--;
- for (i = m; 2*i+1 < n; )
- {
- if (2*i+2 < n
- && fde_compare (ob, a[2*i+2], a[2*i+1]) > 0
- && fde_compare (ob, a[2*i+2], a[i]) > 0)
- {
- SWAP (a[i], a[2*i+2]);
- i = 2*i+2;
- }
- else if (fde_compare (ob, a[2*i+1], a[i]) > 0)
- {
- SWAP (a[i], a[2*i+1]);
- i = 2*i+1;
- }
- else
- break;
- }
- }
- while (n > 1)
- {
- /* Invariant: a[0..n-1] is a heap. */
- n--;
- SWAP (a[0], a[n]);
- for (i = 0; 2*i+1 < n; )
- {
- if (2*i+2 < n
- && fde_compare (ob, a[2*i+2], a[2*i+1]) > 0
- && fde_compare (ob, a[2*i+2], a[i]) > 0)
- {
- SWAP (a[i], a[2*i+2]);
- i = 2*i+2;
- }
- else if (fde_compare (ob, a[2*i+1], a[i]) > 0)
- {
- SWAP (a[i], a[2*i+1]);
- i = 2*i+1;
- }
- else
- break;
- }
+ SWAP (a[0], a[m]);
+ frame_downheap (ob, fde_compare, a, 0, m);