Program to find the sum of each row & column of a matrix of size n x m and
if matrix is square, find the sum of the diagonals also.


#include <iostream.h>
#include <conio.h>
int main()
{
clrscr();
int A[10][10],m,n,x,y,sum=0;
//Create a Matrix A
cout << "Enter number of rows and columns in Matrix A : \n";
cin>>n>>m;
cout << "Enter elements of Matrix A : \n";
for(x=1;x<n+1;++x)
for(y=1;y<m+1;++y)
cin>>A[x][y];
//Find sum of each row
for(x=1;x<n+1;++x)
{
A[x][m+1]=0;
for(y=1;y<m+1;++y)
A[x][m+1]=A[x][m+1]+A[x][y];
}
//Find sum of each column
for(y=1;y<m+1;++y)
{
A[n+1][y]=0;
for(x=1;x<n+1;++x)
A[n+1][y]+=A[x][y];
}
cout << "\nMatrix A, Row Sum (Last Column)" << " and Column Sum (Last Row) : \n";
for(x=1;x<n+1;++x)
{
for(y=1;y<m+2;++y)
cout << A[x][y] << " ";
cout << "\n";
}
//Print sum of each column
x=n+1;
for(y=1;y<m+1;++y)
cout << A[x][y] << " ";
cout << "\n";
if(m==n)
{
for(x=1;x<m+1;x++)
for(y=1;y<n+1;y++)
if(x==y)
sum+=A[x][y];
else
if(y==m-(x+1))
sum+=A[x][y];
}
cout << "Sum of diagonal elements is : " << sum << endl;
getch();
return 0;
}
This program takes in the number of rows (n) and columns (m) as well as the elements as a screen input in a matrix n x m.
It then calculates the sum of each row and each column and outputs it using the 'cout' command.
Also, if it is a square matrix, it calculates the sum of diagonal elements and prints it out.

Sample Input
3 3
9 8 7 6 5 4 3 2 1
Sample Output
Matrix A, Row Sum(Last Column) and Column Sum(Last Row) :
9 8 7 24
6 5 4 15
3 2 1 6
18 15 12
Sum of diagonal elements is : 15