Lower Triangle Sum

Medium 2D Arrays (Matrices)

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Problem Statement

Write a C program to find the sum of elements in the lower triangular part of an N x N matrix (where i >= j).

Input Format

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

Output Format

Print the lower triangle sum.

Constraints

1 <= N <= 10

Sample Input

Sample Output

Explanation

Lower triangle elements: row 0 (1), row 1 (4,5), row 2 (7,8,9). Sum = 1 + 4 + 5 + 7 + 8 + 9 = 34.

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

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