#include <chrono>#include <cstddef>#include <iomanip>#include <iostream>#include <numeric>#include <vector> volatileint sink;// prevents optimization void do_some_work(std::size_t size){std::vector<int> v(size,42);    sink=std::accumulate(v.begin(), v.end(),0);// ensures side effect} int main(){std::cout<<std::fixed<<std::setprecision(9)<<std::left;for(auto size{1ull}; size<1000'000'000ull; size*=100){constauto start= std::chrono::steady_clock::now();        do_some_work(size);constauto end= std::chrono::steady_clock::now();conststd::chrono::duration<double> diff= end- start; std::cout<<"diff = "<< diff<<"; size = "<< size<<'\n';}}

diff = 0.000005415s; size = 1diff = 0.000001986s; size = 100diff = 0.000051633s; size = 10000diff = 0.006043920s; size = 1000000diff = 0.636128648s; size = 100000000