【数据结构】 堆

自底向上：

//增加/减少 已有节点值
Heap_Increase_Key

//向堆插入新的节点
HeapInsert

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自顶向下：

//替换堆顶后，维持堆函数
KeepHeap

//弹出堆顶函数
Pop

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#include <iostream>using namespace std;//增加已有节点值void Heap_Increase_Key(int * array,int& len,int h,int increase_value){    if (array == NULL || h >= len||increase_value<0)        return;    array[h] = increase_value;    int parent = (h -1)/ 2;    while (parent >= 0 &&  array[h] > array[parent])    {        swap(array[h], array[parent]);        h = parent;        parent = (h - 1) / 2;    }}//向堆插入新的节点void HeapInsert(int * array,int & len,int value){    len++;    Heap_Increase_Key(array,len,len-1,value);}//维持堆函数void KeepHeap(int *  array, int len, int h){    int lagest = h;    int leftchild = (h << 1) + 1;//注意移位操作符的优先级低    int rightchild = (h << 1) + 2;    if (leftchild < len && array[h] < array[leftchild])    {        lagest = leftchild;    }    if (rightchild < len && array[lagest] < array[rightchild])    {        lagest = rightchild;    }    if (lagest == h)    {        return;    }    else    {        std::swap(array[h], array[lagest]);        KeepHeap(array, len, lagest);    }}//建堆函数void MakeHeap(int *  array, int len){    if (array == NULL || len <= 1)    {        return;    }    int k = (len - 1) >> 1;    for (auto i = k; i >= 0; --i)//利用keepheap建堆    {        KeepHeap(array, len, i);    }}//弹出堆顶函数void Pop(int *  array, int len){    std::swap(array[len - 1], array[0]);    KeepHeap(array, len - 1, 0);}void HeapSort(int * array, int& len){    MakeHeap(array, len);    Heap_Increase_Key(array, len, 3, 5);    HeapInsert(array, len, 0);    for (auto i = len; i > 1; --i)    {        Pop(array, i);    }}int main(){    int array[15] {3, 2, 4, 1};    int len = 4;    HeapSort(array, len);    return 0;}

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