Write a function int ALTERSUM( int B[][5] , int N, int M) in c++ to find and return the sum of elements from all alternate elements of a two-dimensional array starting from B[0][0].

Hint: If the following is the content of the array

4 5 1

2 8 7

9 6 3

The function should add elements B[0][0], B[0][2], B[1][1], B[2][0], B[2][2]

CBSE 2010

#include<iostream.h>

#include<conio.h>

#define x 10

#define y 5

int ALTERSUM(int B[][5], int M, int N)

{

int flag = 0, sum = 0;

for(int i = 0 ; i < M ; i++)

for(int j = 0 ; j < N ; j++)

{

if(flag == 0)

{ 

   sum = sum + B[i][j];

   flag = 1;

}

else

   flag = 0;

}

return sum;

}

void main()

{

int arr[x][y], r, c, i , j;

cout << "\n How many rows(<10)? " ;

cin >> r;

cout << "\n How many cols(< 5)?";

cin >> c;

/* Input elements */

for( i = 0 ; i < r ; i++)

for(j = 0 ; j< c ; j++)

{

cout << "\n Enter elements :";

cin >> arr[i][j];

}

/* display matrix */

for(i = 0; i < r  ; i++)

for(j = 0; j < c ; j ++)

    cout << arr[i][j] << " ";

cout<< endl;

int sum = ALTERSUM(arr, r, c);

cout << "\n The Sum of alternate elements = " << sum;

getch();

}