Main Diagonal Sum

Problem Statement

Input Format

First line: N. Then N lines of N integers.

Output Format

Print the main diagonal sum.

Constraints

1 <= N <= 10

Sample Input

3
1 2 3
4 5 6
7 8 9

Sample Output

15

Explanation

Main diagonal elements are 1, 5, and 9. Sum = 1 + 5 + 9 = 15.

Starter Code

#include <stdio.h>

int main() {
    int n;
    if (scanf("%d", &n) == 1) {
        int a[n][n];
        for(int i=0; i<n; i++) for(int j=0; j<n; j++) scanf("%d", &a[i][j]);
        // Write your code here
    }
    return 0;
}

Limits

• Time Limit: 1s
• Memory Limit: 256MB