Using 2D array to implement the matrices in java. Below example shows how to take matrix data from the user inputs and display them.
package com.ms.matrix;
import java.util.Scanner;
public class CreateMatrix {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Enter The Number Of Matrix Rows");
int matrixRow = scan.nextInt();
System.out.println("Enter The Number Of Matrix Columns");
int matrixCol = scan.nextInt();
//defining 2D array to hold matrix data
int[][] matrix = new int[matrixRow][matrixCol];
// Enter Matrix Data
enterMatrixData(scan, matrix, matrixRow, matrixCol);
// Print Matrix Data
printMatrix(matrix, matrixRow, matrixCol);
}
public static void enterMatrixData(Scanner scan, int[][] matrix, int matrixRow, int matrixCol){
System.out.println("Enter Matrix Data");
for (int i = 0; i < matrixRow; i++)
{
for (int j = 0; j < matrixCol; j++)
{
matrix[i][j] = scan.nextInt();
}
}
}
public static void printMatrix(int[][] matrix, int matrixRow, int matrixCol){
System.out.println("Your Matrix is : ");
for (int i = 0; i < matrixRow; i++)
{
for (int j = 0; j < matrixCol; j++)
{
System.out.print(matrix[i][j]+"\t");
}
System.out.println();
}
}
}
Below is out of above program.
Enter The Number Of Matrix Rows 3 Enter The Number Of Matrix Columns 3 Enter Matrix Data 34 56 67 35 68 98 86 564 676 Your Matrix is : 34 56 67 35 68 98 86 564 676


Consider a 2D matrix of numbers from 0 to 9 with variable width and height. Find the square submatrix with the highest sum of boundary elements.
Input :
Input width and height of matrix: 6 8
Input Matrix with numbers from 0 to 9:
2 0 6 1 2 5
1 0 5 0 1 3
3 0 1 2 4 1
0 1 3 1 1 9
4 1 0 8 5 2
0 1 0 1 2 3
6 5 3 1 0 2
0 0 1 6 0 4
Input maximum width of square submatrix (for square submatrix height and width are same) : 3
Output :
As sum of highlighted submatrix is maximum (calcute sum of boundary elements only 2,4,1,9,2,5,8,1),
2 0 6 1 2 5
1 0 5 0 1 3
3 0 1 2 4 1
0 1 3 1 1 9
4 1 0 8 5 2
0 1 0 1 2 3
6 5 3 1 0 2
0 0 1 6 0 4
Output should be :
2 4 1
1 1 9
8 5 2
https://stackoverflow.com/questions/49169892/2d-matrix-square-submatrix-with-the-highest-sum-of-boundary