运算效率对比

#除法,乘法,移位耗时对比 发现移位和乘法比除法要省3-5倍时间,移位相对而言是最省时间的

auto time_start = std::chrono::system_clock::now();

int n = 100000;

double d ;

for (int i = 0; i < 1000000; i++)

{

d = n / 2;

}

std::chrono::duration time_spend = std::chrono::system_clock::now() - time_start;

double time_cost = time_spend.count() * 1000;

cout<<"div cost "<

time_start = std::chrono::system_clock::now() ;

for (int i = 0; i < 1000000; i++)

{

d = n * 0.5f;

}

time_spend = std::chrono::system_clock::now() - time_start;

time_cost = time_spend.count() * 1000;

cout<<"muutiple cost "<

time_start = std::chrono::system_clock::now() ;

for (int i = 0; i < 1000000; i++)

{

d = n >>1;

}

time_spend = std::chrono::system_clock::now() - time_start;

time_cost = time_spend.count() * 1000;

cout<<"shit cost "<

return 0;

输出结果如下: div cost 0.000139 ms muutiple cost 3.3e-05 ms shit cost 2.8e-05 ms

原文：https://blog.csdn.net/weixin_40024157/article/details/82898627