计算代码运行时间

包含头文件

#include<time.h>

在程序执行的起始点，插入代码

clock_t start,finish;start=clock();

在程序执行的终点，插入代码：

finish=clock();printf("共耗时%.3lf秒"，((double)finish - start)/1000);

例如，有如下代码：

void swap(int a[], int i, int j){    int temp = a[i];    a[i] = a[j];    a[j] = temp;}

//Sort1void BubbleSort1(int a[], int length){    int i, j;    for (i = 0; i < length - 1; i++)    {        for (j = length - 2; j >= i; j--)        {            if (a[j]>a[j + 1])            {                swap(a, j, j + 1);            }        }    }}

#include<stdlib.h>#include<time.h>#include<stdio.h>#define LENGTH 10int main(){    clock_t start, finish;    start = clock();    srand(unsigned(time(0)));    int a[LENGTH];    printf("排序前：");    for (int k = 9; k >=0; k--)    {//      a[k] = rand()%10000;        a[k] = k + 1;        printf("%d ", a[k]);    }    BubbleSort1(a,LENGTH);    printf("\n排序后：");    for (int i1 = 0; i1 < 10; i1++)    {        printf("%d ", a[i1]);    }    finish = clock();    printf("共耗时%.3lf秒", ((double)finish - start) / 1000);    return 0;}