#include <iostream> 
#include <algorithm> 
 
int main() { 
    const int N = 3, k = 2, matrix[N][N] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}; 
    std::for_each(matrix[k], matrix[k] + N, [d = matrix[k][k]](int& i){ i /= d; }); 
    for(auto& i : matrix) { 
        for(auto j : i) std::cout << j << " "; 
        std::cout << '\n'; 
    } 
}