Java - Find the row and column with the max sum

Question

As the title says, I want to know a way (in Java) to find which row (in a matrix/2D Array) and column has the highest sum of its numbers. There might be an easy solution but I'm struggling to find it.

I currently have the first part of the program but I can't seem to find a solution to the second part, which is finding the row and column with the highest sum.

Desired output

I'm a beginner at this so any kind of advice would be appreciated.

This is the first part of my code:

import javax.swing.JOptionPane;

public class summat{
    public static void main(String[] args){
        int mat[][] = new int [3][3];
        int num, sumop, sumw, i, j, mayop = 0, mayw = 0;

        for(i=0;i<3;i++){
            for(j=0;j<3;j++){
                String input = JOptionPane.showInputDialog(null, "Products sold by the operator " +  (i+1) + " in week " + (j+1) + ".");
                mat[i][j] = Integer.parseInt(input);
            }
        }

        /*Sum of individual rows*/
        for(i=0;i<3;i++){
            sumop = 0;
            for(j=0;j<3;j++){
                sumop = sumop + mat[i][j];
            }
            JOptionPane.showMessageDialog(null, "The operator " + (i+1) + " sold " + sumop + " units.");
        }

        /*Sum of individual columns*/
        for(j=0;j<3;j++){
            sumw = 0;
            for(i=0;i<3;i++){
                sumw = sumw + mat[i][j];
            }
            JOptionPane.showMessageDialog(null, "In week " + (j+1) + " the company sold " + sumw + " units.");
        }

    }
}

Answer 1

You can use the following logic and implement it as desired.

    // Row calculation
    int rowSum = 0, maxRowSum = Integer.MIN_VALUE, maxRowIndex = Integer.MIN_VALUE;
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            rowSum = rowSum + mat[i][j];
        }
        if (maxRowSum < rowSum) {
            maxRowSum = rowSum;
            maxRowIndex = i;
        }
        rowSum = 0;   // resetting before next iteration
    }

    // Column calculation
    int colSum = 0, maxColSum =  Integer.MIN_VALUE, maxColIndex = Integer.MIN_VALUE;
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            colSum = colSum + mat[j][i];
        }
        if (maxColSum < colSum) {
            maxColSum = colSum;
            maxColIndex = i; 
        }
        colSum = 0;    // resetting before next iteration
    }

    System.out.println("Row " + maxRowIndex + " has highest sum = " +maxRowSum);
    System.out.println("Col " + maxColIndex + " has highest sum = " +maxColSum);

Here we use two additional variables maxRowSum to store the highest sum of the row and maxRowIndex to store the index of the highest row. The same applies for column as well.