View Code of Problem 51

#include<iostream>
using namespace std;

int main(void)
{
  int i,j,n,sum,num[10][10]={0};
  cin>>n;sum=0;
  for(i=1;i<=n;++i)
    for(j=1;j<=n;++j)
      cin>>num[i][j];
    for(i=1;i<=n;++i)
      for(j=1;j<=i;++j)
        sum+=num[i][j];
      cout<<sum<<endl;   
}