#include <iostream>
#include <vector>
#include <chrono>

int main(){
    const int N = 5000;
    std::vector<int> initial_row(N, 0);
    std::vector<std::vector< int > > grid(N, initial_row);

    for(auto& row : grid )
        for(auto& elem : row )
            elem = rand()%2;

    double sum = 0.0;
    auto t1 = std::chrono::high_resolution_clock::now();
    for(int i=1; i<N-1; ++i)
        for(int j=1; j<N-1; ++j)
            sum += grid[i][j-1] + grid[i][j+1] + grid[i-1][j] + grid[i+1][j] + grid[i][j]*1.42;
    auto t2 = std::chrono::high_resolution_clock::now();
    auto time_elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(t2-t1).count();
    std::cout << "sum: " << sum << std::endl;
    std::cout << "time for loop: " << time_elapsed << " ms" << std::endl;

    return 0;
}