求5列5行矩阵的主副对角线元素之和给出c++代码

以下是求5x5矩阵主副对角线元素之和的C++代码：

#include <iostream>
using namespace std;

int main() {
    int matrix[5][5] = {{1, 2, 3, 4, 5},
                        {6, 7, 8, 9, 10},
                        {11, 12, 13, 14, 15},
                        {16, 17, 18, 19, 20},
                        {21, 22, 23, 24, 25}};
    int sum_main_diagonal = 0;
    int sum_secondary_diagonal = 0;

    for (int i = 0; i < 5; i++) {
        sum_main_diagonal += matrix[i][i];
        sum_secondary_diagonal += matrix[i][4-i];
    }

    cout << "Sum of main diagonal elements: " << sum_main_diagonal << endl;
    cout << "Sum of secondary diagonal elements: " << sum_secondary_diagonal << endl;

    return 0;
}

注意：以上代码中的矩阵元素是手动输入的，你可以根据需要修改矩阵元素。