这里用数组（顺序表）实现一个二叉树

Heap.h

#include<stdio.h>
#include<stdlib.h>
#include<assert.h>
#include<stdbool.h>
typedef int HPDataType;
typedef struct Heap
{HPDataType* a;int size;int capacity;
}HP;
void HPInit(HP* php);
void HPDestory(HP* php);
void Swap(HPDataType* p1, HPDataType* p2);
void AdjustUp(HP* php, int child);
void AdjustDown(HP* php);
void HPPush(HP* php, HPDataType x);
void HPPop(HP* php);
HPDataType HPTop(HP* php);
int HPSize(HP* php);
bool ISEmpty(HP* php);

Heap.c

#include"Heap.h"
void HPInit(HP* php)
{assert(php);php->a = NULL;php->size = php->capacity = 0;
}
void HPDestory(HP* php)
{assert(php);free(php->a);php->a = NULL;php->size = php->capacity = 0;
}
//交换函数：
void Swap(HPDataType* p1, HPDataType* p2)
{HPDataType tmp = *p1;*p1 = *p2;*p2 = tmp;
}
//向上调整元素：（小堆）
void AdjustUp(HP* php,int child)
{assert(php);assert(php->size);int parent = (child - 1) / 2;while (child != parent){if (php->a[child] < php->a[parent]){Swap(&php->a[child], &php->a[parent]);parent = child;parent = (child - 1) / 2;}elsebreak;}
}
//向下调整：（小堆）
void AdjustDown(HP* php)
{assert(php);int parent = 0;int child = 2 * parent + 1;while (child<php->size){if (child+1<php->size&&php->a[child] > php->a[child + 1])child = child + 1;if (php->a[parent] > php->a[child]){Swap(&php->a[parent], &php->a[child]);parent = child;child = 2 * child + 1;}elsebreak;}
}
//插入元素：
void HPPush(HP* php, HPDataType x)
{int newcapacity = (php->capacity == 0) ? 4 : php->capacity * 2;if (php->capacity == php->size){HPDataType* tmp = (HPDataType*)realloc(php->a, sizeof(HPDataType) * newcapacity);php->a = tmp;}php->a[php->size] = x;php->size++;AdjustUp(php, php->size - 1);
}
//删除堆顶元素：
void HPPop(HP* php)
{assert(php);assert(php->size);Swap(&php->a[php->size - 1], &php->a[0]);php->size--;AdjustDown(php);
}
//取出栈顶元素：
HPDataType HPTop(HP* php)
{assert(php);assert(php->size);return php->a[0];
}
//计算元素个数：
int HPSize(HP* php)
{assert(php);assert(php->size);return php->size;
}
//判断堆是否为空：
bool ISEmpty(HP* php)
{assert(php);return php->size == 0;
}

test.c

#include"Heap.h"
int main()
{int arr[10] = { 5,9,1,3,7,6 };HP hp;HPInit(&hp);int sz = sizeof(arr) / sizeof(int);for (int i = 0;i <6;i++){HPPush(&hp, arr[i]);}while (!ISEmpty(&hp)){int k = HPTop(&hp);printf("%d ", k);HPPop(&hp);}printf("\n");return 0;
}