View Code of Problem 51

#include<stdio.h>
#include<string.h>
#include<math.h>
int main()
{
	int n;
	scanf("%d",&n);
	int a[n][n];
	int i,j;
	for(i=0;i<n;i++)
	{
		for(j=0;j<n;j++)
		{
			scanf("%d",&a[i][j]);
		}
	}
	int sun=0;
	for(i=0;i<n;i++)
	{
		for(j=0;j<i+1;j++)
		{
			sum+=a[i][j];
		}
	}
	printf("%d\n",sum);
}
/*
Main.c: In function 'main':
Main.c:22:4: error: 'sum' undeclared (first use in this function); did you mean 'sun'?
    sum+=a[i][j];
    ^~~
    sun
Main.c:22:4: note: each undeclared identifier is reported only once for each function it appears in
Main.c:17:6: warning: unused variable 'sun' [-Wunused-variable]
  int sun=0;
      ^~~
*/