54 lines
1.2 KiB
C
54 lines
1.2 KiB
C
#include "heap.h"
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static int parent(int i) {
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return (i > 0) ? (i - 1) / 2 : -1;
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}
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static int left_child(int i) {
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return i * 2 + 1;
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}
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static int right_child(int i) {
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return i * 2 + 2;
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}
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static int left_sibling(int i) {
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return (i % 2 == 0) ? i - 1 : -1;
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}
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static int right_sibling(int i) {
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return (i % 2 == 1) ? i + 1 : -1;
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}
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static int index_of_larger_child(int i, dlos_Heap *h) {
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int larger = left_child(i);
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if (larger >= h->size) {
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return -1;
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}
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if (larger + 1 < h->size && h->compare(&h->arr[larger], &h->arr[larger + 1]) > 0) {
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larger = larger + 1;
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}
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return larger;
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}
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void dlos_node_swap(dlos_ComparableNode *arr, int a, int b) {
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dlos_ComparableNode temp = arr[a];
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arr[a] = arr[b];
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arr[b] = temp;
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}
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void dlos_sift_down(int i, dlos_Heap *h) {
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int target = index_of_larger_child(i, h);
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while (target > 0 && h->compare(&h->arr[i], &h->arr[target]) > 0) {
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dlos_node_swap(h->arr, i, target);
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i = target;
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target = index_of_larger_child(i, h);
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}
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}
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void dlos_max_heap(dlos_Heap *h) {
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for (int i = parent(h->size - 1); i >= 0; i--) {
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dlos_sift_down(i, h);
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}
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}
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