c计时函数

0.head file

#include <ctime>

1.time(NULL)

int64 begin_time = time(NULL);//time_t
int64 end_time = time(NULL);
int64 interval = end_time - begin_time;//second 

2.clock()

long begin_clock_=clock();//clock_t
long end_clock_=clock();
long interval_ms = (end_time - begin_time);
double interval_s = (double)interval_ms/CLOCKS_PER_SEC;//second

3.windows平台提供的一些即时函数

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