Chapter 8 Exercise 14, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

**8.14 (Explore matrix) Write a program that prompts the user to enter the length of a square matrix, randomly fills in 0s and 1s into the matrix, prints the matrix, and finds the rows, columns, and diagonals with all 0s or 1s. Here is a sample run of the program: Enter the size for the matrix: 4 0111 0000 0100 1111 All 0s on row 1 All 1s on row 3 No same numbers on a column No same numbers on the major diagonal No same numbers on the sub-diagonal

import java.util.Scanner;
 
 
 
public class ProgrammingEx8_14 {
 
 public static void main(String[] args) {
  Scanner input = new Scanner(System.in);
  System.out.print("Enter the size for the matrix: ");
  int intSize = input.nextInt();
 
  int[][] intMetrix = new int[intSize][intSize];
  fillMetrix(intMetrix);
  displayMetrix(intMetrix);
  checkMetrix(intMetrix);
 }
 
 public static int intRandom(int lowerBound, int upperBound) {
  return (int) (lowerBound + Math.random()
    * (upperBound - lowerBound + 1));
 }
 
 public static void fillMetrix(int metrix[][]) {
  for (int i = 0; i < metrix.length; i++) {
   for (int j = 0; j < metrix[i].length; j++) {
    metrix[i][j] = intRandom(0, 1);
   }
 
  }
 
 }
 
 public static void checkMetrix(int metrix[][]) {
 
  boolean blnFound = false;
  // Checking row
  for (int i = 0; i < metrix.length; ++i) {
   int intResult = checkRow(i, metrix);
   if (intResult != 2) {
    blnFound = true;
    System.out.println("All " + intResult + "s on row " + i);
   }
  }
 
  if (blnFound == false) {
 
   System.out.println("No same numbers on a row");
  }
 
  // Checking column
  blnFound = false;
  for (int i = 0; i < metrix.length; ++i) {
   int intResult = checkCol(i, metrix);
   if (intResult != 2) {
    blnFound = true;
    System.out.println("All " + intResult + "s on column " + i);
   }
  }
 
  if (blnFound == false) {
 
   System.out.println("No same numbers on a column");
  }
 
  // Checking major diagonals
 
  int intMajor = checkMajorDia(metrix);
  int intMinor = checkMinorDia(metrix);
 
  if (intMajor != 2) {
   System.out.println("All " + intMajor + "s on major diagonal");
  } else {
   System.out.println("No same numbers on the major diagonal");
  }
 
  if (intMinor != 2) {
   System.out.println("All " + intMinor + "s on sub-diagonal");
  } else {
   System.out.println("No same numbers on the sub-diagonal");
  }
 
 }
 
 public static void displayMetrix(int metrix[][]) {
 
  for (int i = 0; i < metrix.length; i++) {
   for (int j = 0; j < metrix[i].length; j++) {
    System.out.print(metrix[i][j]);
   }
 
   System.out.println("");
  }
 
 }
 
 // Return 2 if the row is not repeating. Return number 0 or one if it is
 public static int checkRow(int intRow, int intMetrix[][]) {
 
  for (int i = 1; i < intMetrix[intRow].length; i++) {
   if (intMetrix[intRow][i] != intMetrix[intRow][0])
    return 2;
  }
  return intMetrix[intRow][0];
 
 }
 
 public static int checkCol(int intCol, int intMetrix[][]) {
  for (int i = 1; i < intMetrix.length; i++) {
   if (intMetrix[i][intCol] != intMetrix[0][intCol])
    return 2;
  }
  return intMetrix[0][intCol];
 }
 
 // Check major diagonal where i = j or from top left to lower right
 public static int checkMajorDia(int intMetrix[][]) {
  for (int i = 1; i < intMetrix.length; i++) {
   if (intMetrix[i][i] != intMetrix[0][0])
    return 2;
  }
  return intMetrix[0][0];
 }
 
 // Check major diagonal where i = metrix size - i or from lower left to
 // upper right
 public static int checkMinorDia(int intMetrix[][]) {
  int intSize = intMetrix.length - 1;
  for (int i = 1; i < intMetrix.length; i++) {
   if (intMetrix[i][intSize - i] != intMetrix[0][intSize])
    return 2;
  }
  return intMetrix[0][0];
 }
 
}