Matrix.java

import java.util.Scanner;
class Matrix {
    private static int row;
    private static int[][] matrix;
    private static int[][] temp;
    public static void main(String[] args) {
		System.out.println("Enter the number of rows in the square matrix: ");
		Scanner input = new Scanner(System.in);
		row = input.nextInt();
		matrix = new int[row][row];
		temp = new int[row][row];

		System.out.println("Enter the matrix row by row: ");
		for (int i = 0; i != row; i++) {
		    for (int j = 0; j != row; j++) {
			matrix[i][j] = input.nextInt();
		    }	
		}

		System.out.println("input:");
		for (int i = 0; i != row; i++) {
		    for (int j = 0; j != row ; j++) {
				System.out.print(matrix[i][j]);
			
		    }
		    System.out.println("");
		}

		System.out.println("output:");
		
		for (int i = row-1; i >= 0; i--) {
		    for (int j = row-1; j >= 0; j--) {
				temp[i][j] = calc (i, j);
		    }
		}

		for (int i = 0; i != row; i++) {
		    for (int j = 0; j != row ; j++) {
			System.out.print(temp[i][j]);		
		    }
		    System.out.println("");
		}
		
		printResult();

    }

    private static int calc(int x, int y) {
		if (matrix[x][y] == 0) {
		    return 0;
		} else {
		    if ((x == row - 1) || (y == row - 1)) {
				
				return 1;
		    } else {
			if ((matrix[x+1][y] == 0) || (matrix[x][y+1] == 0) || (matrix[x+1][y+1] == 0)) {
			    return 1;
			} else if ((temp[x+1][y] != temp[x+1][y+1]) || (temp[x][y+1] != temp[x+1][y+1])) {
			    return 1;
			} else {
			    return calc(x+1, y+1) + 1;
			}
		}
	}

    }
    private static void printResult() {
		int x = 0;
		int y = 0;
		int min = 0;
		for (int i = 0; i != row; i++) {
		    for (int j = 0; j != row; j++) {
				if (temp[i][j] >= min) {
				    x = j;
				    y = i;
				    min = temp[i][j];
				}
		    }
		}

		System.out.println("the largest block is at(" + x + ", " + y + ") with " + min +" rows.");
    }
}