Matrix - Sum of Edge Elements -C

The input elements of R*C matrix is passed as the input (R is the number of rows and C is the number of columns in the matrix. The program must print the sum S of the elements along the edge of the matrix. 

Input Format: The first line contains R and C separated by a space.. Next R lines contain C values each, with the values separated by a space.

Output Format: The first line contains S.

Boundary Conditions:

• 2 <= R, C <= 100 
• 1 <= Matrix Cell Value <= 1000

Example Input/Output 1:

Input:

5 3 

1 2 3 

4 5 6 

7 8 9 

5 5 5 

2 2 2 

Output:48 

Example Input/Output 2: 

Input: 

3 3 

100 200 300 

400 500 600 

700 800 900 

Output:

4000

          

Source Code:

#include<stdio.h>

#include <stdlib.h>

int main()

{

int r,c,i,j,s=0;

scanf("%d%d",&r,&c);

int m[r][c];

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

{

    for(j=0;j<c;j++)

    {

        scanf("%d",&m[i][j]);

        if(i>0&&i<r-1)

        {

            if(j==0||j==c-1)

            s+=m[i][j];

        }

        else

        s+=m[i][j];

    }

}

printf("%d",s);

}