Linux_cpp_測試

diff.cpp

#include <stdio.h>
#include <chrono>
#include <iostream>

double testloop(const int *a, const int len){
   double sum = 0;
   for(int i=0;i< len;i++){
     if (a[i]%2==0)
        sum+=a[i];
   }
   return sum;
}

int main(){
    const int len=10000000;
    int *a = new int[len];
    for(int i=0;i<len;i++){
        a[i]=i;
    }
    std::chrono::steady_clock::time_point begin=std::chrono::steady_clock::now();
    testloop(a, len);
    std::chrono::steady_clock::time_point end = std::chrono::steady_clock::now();
    std::cout <<"time diff    " << std::chrono::duration_cast<std::chrono::microseconds>(end-begin).count() <<"[us]"<<
std::endl;
    return 0;
}