View Code of Problem 51

#include<stdio.h>
#include <math.h>
#include<string.h>
int main() {
    int n;
    int sum = 0;
    scanf("%d", &n);
    int str1[10][10];
    int i, j;
    for (i = 0; i < n; i++) {
        for (j = 0; j < n; j++) {
            scanf("%d", &str1[i][j]);
        }
    }
    for (i = 0; i < n; i++) {
        for (j = 0; j <= i; j++) {
            sum += str1[i][j];
        }
    }

    printf("%d", sum);
    return 0;
}