Вычисление максимального элемента побочной диагонали матрицы

#include <iostream>
#include <ctime>
#include <algorithm>
#include <iterator>
#define N 5
 
int f(int [N][N]);
 
int main()
{
    srand( time(0) );
    int A[N][N], B[N][N], C[N][N];
    std::for_each(A, A + N, [] (int* value) 
        {std::generate(value, value + N, [] {return rand() % 10; } ); } );
    std::for_each(A, A + N, [] (int* value) 
        {std::copy(value, value + N, std::ostream_iterator<int> (std::cout, " ")); std::cout<< std::endl;} );
    std::cout<< f(A)<< std::endl<< std::endl; 
    std::for_each(B, B + N, [] (int* value) 
        {std::generate(value, value + N, [] {return rand() % 10; } ); } );
    std::for_each(B, B + N, [] (int* value) 
        {std::copy(value, value + N, std::ostream_iterator<int> (std::cout, " ")); std::cout<< std::endl;} );
    std::cout<< f(B)<< std::endl<< std::endl; 
    std::for_each(C, C + N, [] (int* value) 
        {std::generate(value, value + N, [] {return rand() % 10; } ); } );
    std::for_each(C, C + N, [] (int* value) 
        {std::copy(value, value + N, std::ostream_iterator<int> (std::cout, " ")); std::cout<< std::endl;} );
    std::cout<< f(C)<< std::endl<< std::endl;   
    return 0;
} 
 
int f(int arr[N][N])
{
    int tmp[N];
    for (std::size_t i=0; i < N; i++)
        tmp[i] = arr[N - i -1][i];
    return *std::max_element(tmp, tmp + N);  
}