C/C++实践笔记 025堆排序、CGI网页交互

1.堆与堆排序
堆在数据结构里是二叉树
堆排序取出一个最大值、最小值最快

#include<stdio.h>
#include<stdlib.h>
void show(int *p, int n)
{
    for (int i = 0; i < n; i++)
    {
        printf("%4d", p[i]);
    }
    printf("\n");


}
void findmax(int *arr,int size)
{
    for (int j = size - 1; j>0; j--)//从尾循环到头部，自下而上登顶
    {
        int parent = j / 2;
        int child = j; //记录当前下标
        if (j < size - 1 && arr[j] < arr[j + 1])//先取出左右最大值
        {
            child++;
        }
        if (arr[child] > arr[parent]) //最大值登顶
        {
            int temp = arr[child];
            arr[child] = arr[parent];
            arr[parent] = temp;
        }
    }

}
void heapsort(int *arr, int size)
{
    for (int j = size; j > 0; j--)
    {
        findmax(arr, j);
        
        int temp = arr[0];
        arr[0] = arr[j - 1];
        arr[j - 1] = temp;
    }


}
void main()
{
    int a[10] = { 10,13,20,12,30,14,50,19,60,29 };
    //show(a, 10);
    //findmax(a, 10);
    //show(a, 10);
    heapsort(a, 10);
    show(a, 10);
    system("pause");

}

 

2.CGI网页交互

printf("Content-type:text/html \n\n");

gets(str);