Question

Language: Java

So I am trying to find the MAJOR and MINOR diagonal SUM and AVERAGE of a 2d matrix using only ONE class. However, the output gives me the incorrect calculations.

This is my class:

public static void MajorAndMinorDiagonalSumAndAvg (Scanner user, int rows, int coluumn, int [][] array) {

double majorarray = 0; double majorarraycount = 0; double minorarray = 0; double minorarraycount = 0;

for (int i = 0; i<array.length; i++)

for(int j =0; j<array[i].length; j++)

{

majorarray += array[i][i];

majorarraycount++;

minorarray += array[i][array.length - i-1];

minorarraycount++;

}

System.out.printf("Major Diagonal Sum: " + "%.2f", majorarray);

System.out.println();

System.out.printf("Major Diagonal Avg: " + "%.2f",majorarray/majorarraycount);

System.out.println();

System.out.printf("Minor Diagonal Sum: " + "%.2f",minorarray);

System.out.println();

System.out.printf("Minor Diagonal Avg: " + "%.2f",minorarray/minorarraycount);

System.out.println();

}

What should I change to get the correct calculations?

Answer 1

public class DiagonalSum {

// method to calculate the MAJOR and MINOR diagonal SUM and AVERAGE of a 2d matrix

// remove user, rows and column parameters from method since they are not used in the function

       public static void MajorAndMinorDiagonalSumAndAvg (int [][] array) {

             double majorarray = 0, majorarraycount = 0, minorarray = 0, minorarraycount = 0;

            

             // loop over the rows of the input matrix

             for(int i=0;i<array.length;i++)

             {

                    majorarray += array[i][i]; // calculate sum of major axis

                    majorarraycount++; // calculate number of elements in major axis

                    minorarray += array[i][array.length-i-1]; // calculate sum of minor axis

                    minorarraycount++; // calculate number of elements in minor axis

             }

            

             // output

             System.out.printf("Major Diagonal Sum: " + "%.2f", majorarray);

             System.out.println();

             System.out.printf("Major Diagonal Avg: " + "%.2f",majorarray/majorarraycount);

             System.out.println();

             System.out.printf("Minor Diagonal Sum: " + "%.2f",minorarray);

             System.out.println();

             System.out.printf("Minor Diagonal Avg: " + "%.2f",minorarray/minorarraycount);

             System.out.println();

                   

       }

      

       public static void main(String[] args){

            

            

             // test the method

             int array[][] = {{1,2,3,4,5},{1,2,3,4,5},{1,2,3,4,5},{1,2,3,4,5},{1,2,3,4,5}};

             for(int i=0;i<array.length;i++)

             {

                    System.out.println();

                    for(int j=0;j<array[i].length;j++)

                           System.out.print(array[i][j]+" ");

             }

             System.out.println();

             MajorAndMinorDiagonalSumAndAvg(array);

}

}

//end of program

Output: