C++计时的两种方式

#include< ctime >

using namespace std;
clock_t time_start=clock();
//...
clock_t time_end=clock();
cout<<"time use:"<<1000*(time_end-time_start)/(double)CLOCKS_PER_SEC<<"ms"<

#include< chrono >

using namespace std;
chrono::steady_clock::time_point time_start=chrono::steady_clock::now();
//....
chrono::steady_clock::time_point time_end=chrono::steady_clock::now();
chrono::duration time_used=chrono::duration_cast>(time_end-time_start);
cout<<"time use:"<