c语言time与clock区别

#include<stdio.h>#include <time.h>int main(){long i=0;float j=0;clock_t start_clock=clock();time_t start_time=time(NULL);for(i=0;i<100000000;i++){j=(float)i*213124/200000;}//sleep(3);printf("processor time used is:%g sec. ,j= %d \n",(clock()-start_clock)/(double) CLOCKS_PER_SEC,j);printf("Running time :%g sec. \n",difftime(time(NULL),start_time));return 0;}

程序运行结果：

processor time used is:0.71 sec. ,j= 1073741824 Running time :1 sec. 

clock记录的是该程序在处理器中运算所占用的时间

time记录的是整个程序从开始运行到最后结束所消耗的时间