MatrixSumming2.java SOLUTION

//(c) A+ Computer Science
//www.apluscompsci.com
//Name -

import java.util.*;
import java.io.*;

public class MatrixSumming2
{
    public static int sum( int[][] mat, int r, int c )
    {
        int total = 0;
      total += mat[r][c];
      if( r - 1 >= 0 && c - 1 >= 0 ) total += mat[r-1][c-1];
      if( r - 1 >= 0 ) total += mat[r-1][c];
      if( r - 1 >= 0 && c + 1 < mat[0].length ) total += mat[r-1][c+1];
      if( c - 1 >= 0 ) total += mat[r][c-1];
      if( c + 1 < mat[0].length ) total += mat[r][c+1];
      if( r + 1 < mat.length && c - 1 >= 0 ) total += mat[r+1][c-1];
      if( r + 1 < mat.length ) total += mat[r+1][c];
      if( r + 1 < mat.length && c + 1 < mat.length ) total += mat[r+1][c+1];
      return total;
    }

    public static void main(String[] args){
        int[][] m = {{1, 2, 3, 4, 5},
                        {6, 7, 8, 9, 0},
                        {6, 7, 1, 2, 5},
                        {6, 7, 8, 9, 0},
                        {5, 4, 3, 2, 1}};
        System.out.println( sum(m, 2, 2) );
        System.out.println( sum(m, 0, 0) );
        System.out.println( sum(m, 4, 3) );
        System.out.println( sum(m, 4, 4) );
        System.out.println( sum(m, 2, 4) );
        System.out.println( sum(m, 1, 3) );

     }
}