数据结构-树-C语言-堆

#include <stdio.h>
#include <stdlib.h>
 
typedef struct HeapStruct *pHeap;//pHeap为结构指针，指向这个结构
struct HeapStruct {
    int *data;        //模拟放入的数据
    int size;        //已存在的元素个数
    int capacity;    //堆容量
};
typedef pHeap MaxHeap;
typedef pHeap MinHeap;
 
#define MAXDATA 1000
#define ERROR -999
 
MaxHeap createHeap(int maxSize) {
    MaxHeap heap = (MaxHeap)malloc(sizeof(struct HeapStruct));
    heap->data = (int *)malloc(++maxSize*sizeof(int));
    heap->size = 0;
    heap->capacity = maxSize;
    heap->data[0] = MAXDATA;
    return heap;
}
 
bool isFull(MaxHeap heap) {
    return heap->capacity <= heap->size;
}
 
bool isEmpty(MaxHeap heap) {
    return heap->size == 0;
}
 
bool insert(MaxHeap heap, int item) {
    int i;
    if (isFull(heap)) {
        printf("Heap is Full");
        return false;
    }
    i = ++heap->size;
    for (; heap->data[i / 2] < item;i/=2) {
        heap->data[i] = heap->data[i / 2];
    }
    heap->data[i] = item;
    return true;
}
 
/*
@program 思想为将根节点的元素删除，将最后一个元素设置为temp
@program 通过循环为temp找到合适的位置插入其中
*/
int deleteMax(MaxHeap heap) {
    int parent, child;
    int maxItem, temp;
    if (isEmpty(heap)) {
        printf("Heap is Empty");
        return ERROR;
    }
    maxItem = heap->data[1];
    temp = heap->data[heap->size--];
    for (parent = 1; parent * 2 <= heap->size;parent=child) {
        child = parent * 2;
        if ((heap->data[child] < heap->data[child+1]) && child!=heap->size) {
            child++;
        }
        if (temp >= heap->data[child]) break;
        else heap->data[parent] = heap->data[child];
    }
    heap->data[parent] = temp;
    return maxItem;
}
 
/*
@program 将堆结构中data[p]的下方的堆结构修改为最大堆
@param heap 最大堆的结构指针
@param p 
*/
void percDown(MaxHeap heap, int p) {
    int parent, child;
    int temp;
    temp = heap->data[p];
    for (parent = p; parent * 2 <= heap->size; parent = child) {
        child = parent * 2;
        if ((heap->data[child] < heap->data[child + 1]) && child != heap->size) {
            child++;//返回的是左右子树中较大的data
        }
        if (temp >= heap->data[child]) break;
        else heap->data[parent] = heap->data[child];
    }
    heap->data[parent] = temp;
}
 
void buildMaxHeap(MaxHeap heap) {
    for (int i = heap->size / 2; i > 0; i--) {
        percDown(heap, i);
    }
}