void generic_heap_move_down(generic_heap_t *heap, int32_t x) {
uint32_t i;
assert(0 <= x && x < heap->idx_size && heap->idx[x] >= 0);
i = heap->idx[x];
heap_update_down(heap, x, i);
}
/*
* Remove x from the heap
* - no change if x is not there
*/
void int_heap_remove(int_heap_t *heap, int32_t x) {
assert(x >= 0);
if (x >= heap->idx_size || heap->idx[x] < 0) return; // not there
heap_update_down(heap, heap->idx[x]);
heap->idx[x] = -1;
}
/*
* Get the smallest element and remove it
* - return -1 if the heap is empty
*/
int32_t int_heap_get_min(int_heap_t *heap) {
uint32_t n;
int32_t x;
n = heap->nelems;
if (n == 0) return -1;
x = heap->heap[1];
heap_update_down(heap, 1);
heap->idx[x] = -1;
return x;
}
/*
* Get the smallest element and remove it
* - return -1 if the heap is empty
*/
int32_t generic_heap_get_min(generic_heap_t *heap) {
uint32_t n;
int32_t x, y;
n = heap->nelems;
if (n == 0) return -1;
x = heap->heap[1];
y = heap->heap[n];
heap->nelems = n - 1;
if (x != y) {
heap_update_down(heap, y, 1);
}
heap->idx[x] = -1;
return x;
}
/*
* Remove x from the heap
* - no change if x is not there
*/
void generic_heap_remove(generic_heap_t *heap, int32_t x) {
uint32_t n;
int32_t y;
assert(x >= 0);
if (x >= heap->idx_size || heap->idx[x] < 0) return; // not there
// move last element into the subtree of root x
n = heap->nelems;
y = heap->heap[n];
heap->nelems = n - 1;
if (x != y) {
heap_update_down(heap, y, heap->idx[x]);
}
heap->idx[x] = -1;
}
void generic_heap_update(generic_heap_t *heap, int32_t x) {
uint32_t i, n;
int32_t y;
assert(0 <= x && x < heap->idx_size && heap->idx[x] >= 0);
i = heap->idx[x];
n = heap->nelems;
if (i == n) {
heap_update_up(heap, x, i);
} else {
// remove x, replace it by y = last heap element
y = heap->heap[n];
heap->nelems = n - 1;
heap_update_down(heap, y, i);
// put x back in
heap->nelems = n;
heap_update_up(heap, x, n);
}
}
