Chapter 5 Exercise 18, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

*5.18 (Display four patterns using loops) Use nested loops that display the following patterns in four separate programs:
Pattern A
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
1 2 3 4 5 6

Pattern B
1 2 3 4 5 6
1 2 3 4 5
1 2 3 4
1 2 3
1 2
1


Pattern C
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
1 2 3 4 5 6

Pattern D

1 2 3 4 5 6
   1 2 3 4 5
      1 2 3 4
         1 2 3
            1 2
               1

import java.util.Scanner;
 
public class ProgrammingEx5_18A {
 
 public static void main(String[] args) {
  System.out.print("Enter the number of lines:");
  Scanner input = new Scanner(System.in);
 
  // get the total number of lines n.
  int n = input.nextInt();
 
  // Loop through the lines from 1 to n
  System.out.println("Pattern A");
  for (int i = 1; i <= n; i++) {
 
   // Printing number increamentally from 1 to line number j
   for (int j = 1; j <= i; j++) {
    System.out.print(j + " ");
   }
   System.out.println();
 
  }
 
 }
 
}

import java.util.Scanner;
 
public class ProgrammingEx5_18B {
 
 public static void main(String[] args) {
  System.out.print("Enter the number of lines:");
  Scanner input = new Scanner(System.in);
 
  // get the total number of lines n.
  int n = input.nextInt();
 
  // Loop through the lines from 1 to n (i=0 to n-1
  System.out.println("Pattern B");
  for (int i = 0; i < n; i++) {
 
 
 
   // Printing number increamentally from 1 to line number j
   for (int j = 1; j <= n - i; j++) {
    System.out.print(j + " ");
   }
   System.out.println();
 
  }
 
 }
 
}

import java.util.Scanner;
 
public class ProgrammingEx5_18C{
 
 public static void main(String[] args) {
  System.out.print("Enter the number of lines:");
  Scanner input = new Scanner(System.in);
   
  //get the total number of lines n.
  int n = input.nextInt();
 
  //Loop through the lines from 1 to n
  System.out.println("Pattern C");
  for (int i = 1; i <= n; i++) {
   // printing spaces, 2 at a time from j=1 to j= n-i 
   for (int j = 1; j <= (n - i); j++) {
    System.out.print("  ");
   }
    
   //Printing number increamentally from 1 to line number j
   for (int j = 1; j <= i; j++) {
    System.out.print(j + " ");
   }
   System.out.println();
 
  }
 
  }
 
 }

import java.util.Scanner;
 
public class ProgrammingEx5_18D{
 
 public static void main(String[] args) {
  System.out.print("Enter the number of lines:");
  Scanner input = new Scanner(System.in);
   
  //get the total number of lines n.
  int n = input.nextInt();
   
  //Loop through the lines from 1 to n (i=0 to n-1)
  System.out.println("Pattern C");
  for (int i = 0; i < n; i++) {
    
   // printing spaces, 2 at a time from j=i to 0
   for (int j = i; j>0; j--) {
    System.out.print("  ");
   }
    
   //Printing number increamentally from 1 to line number j
   for (int j = 1; j <= n-i; j++) {
    System.out.print(j + " ");
   }
   System.out.println();
 
  }
 
 }
 
}