This C Program finds the sum of the main & opposite diagonal elements of a MxN Matrix. The program accepts an MxN matrix. Then adds main diagonal of matrix as well as the opposite diagonal of the matrix.

Here is source code of the C program to finds the sum of the main & opposite diagonal elements of a MxN Matrix. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

`/*`

`* C program to find accept a matrix of order M x N and find`

`* the sum of the main diagonal and off diagonal elements`

`*/`

`#include <stdio.h>`

void main ()

`{`

static int array[10][10];

int i, j, m, n, a = 0, sum = 0;

printf("Enetr the order of the matix \n");

scanf("%d %d", &m, &n);

if (m == n )

`{`

printf("Enter the co-efficients of the matrix\n");

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

`{`

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

`{`

scanf("%d", &array[i][j]);

`}`

`}`

printf("The given matrix is \n");

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

`{`

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

`{`

printf(" %d", array[i][j]);

`}`

printf("\n");

`}`

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

`{`

sum = sum + array[i][i];

a = a + array[i][m - i - 1];

`}`

printf("\nThe sum of the main diagonal elements is = %d\n", sum);

printf("The sum of the off diagonal elemets is = %d\n", a);

`}`

`else`

printf("The given order is not square matrix\n");

`}`

$ cc pgm83.c $ a.out Enetr the order of the matix 2 2 Enter the co-efficients of the matrix 40 30 38 90 The given matrix is 40 30 38 90 The sum of the main diagonal elements is = 130 The sum of the off diagonal elemets is = 68

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