#include<iostream> using namespace std; int main() { int n; cout << "请输入矩阵的维数n: "; cin >> n; int matrix[n][n]; int sum = 0; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { cin >> matrix[i][j]; if (i == j) { sum += matrix[i][j]; // 对角线元素相加 } } } cout << "矩阵对角线之和为: " << sum << endl; return 0; }