c 2b 2b program for addition of two matrix in diagonal using pointers

1/* C++ program for Sum of diagonal elements of a matrix */
2#include<iostream>
3using namespace std;
4int main()
5{
6	int matrix[100][100], m, n ,i ,j, sum=0;
7	cout<<"Enter rows of matrix: ";
8	cin>>m;
9	cout<<"Enter columns of matrix: ";
10	cin>>n;
11 
12	cout<<"Enter matrix elements: "<<endl;
13	for(i=0;i<m;i++)
14	{
15		for(j=0;j<n;j++)
16		{
17			cin>>matrix[i][j];
18		}
19	}
20 
21	/* add diagonal elements into sum */
22	for(i=0;i<m;i++)
23	{
24		for(j=0;j<n;j++)
25		{
26			if(i==j)
27			sum=sum+matrix[i][j];
28		}
29	}
30 
31	cout<<"Sum of diagonal elements: "<<sum;
32 
33	return 0;	
34}