#include <iostream>
#include <vector>

int main() {
    std::vector<std::vector<int>> matrix(3, std::vector<int>(3,0));

    for(int i=0; i<3;i++){
        for(int j=0; j<3;j++){
            matrix[i][j] = j;
            matrix[i][j] = i;
        }
    }

    for(const auto &row : matrix){
        for(const auto &elem : row){
            std::cout<<elem<<" ";
        }
        std::cout<<std::endl;
    }
}

Embed on website

To embed this project on your website, copy the following code and paste it into your website's HTML: