Hi everyone … I will share some java source code which will help beginner level programmer to solve basic programming problems..

All code has been solved by : Afjalur Rahman Rana

Note: firstly try to solve the problem by yourself.. then if you can’t see the solution & if you find difficulty to any code then comment below… I will try to give you proper guide 🙂

Problem  #11:

Triangle – Right Justified
Draw right angled triangle of given height
Sample input:

Sample input:
4
Sample output
4
34
234
1234

Solution:

import java.util.Scanner;
public class Task11{
  public static void main(String[] args){
    int n;
    int space=0;
    Scanner sc = new Scanner(System.in);
    
    System.out.print("Input row");
    int row = sc.nextInt();
    
    for(int r = 1 ;r<=row;r++){
      //while row is increasing space is decreasing
      for(space = 1;space<=row-r;space++){
        System.out.print(" ");
        
      }
      for(int c=space;c<=row;c++){
      System.out.print(c);
    }
    System.out.print("\n");
    }
  
  }
}

Problem  #12:

Rhombus
Just draw the image of the above triangle once. And then, the opposite, once.

Sample input:
3
Sample output
*
***
*****
***
*

Solution:

import java.util.Scanner;
public class Task12{
  public static void main(String[] args){
    int n;
    Scanner sc = new Scanner(System.in);
    
    System.out.print("Input row");
    int row = sc.nextInt();
    row*=2;
    int j =1;
    int k=1;
    
    for(int r = 1 ;r<row;r++){
      if(r<=row/2){
      //while row is increasing space is decreasing
      for(int space = 1;space<=row/2-r;space++){
      System.out.print(" ");
      }
      for(int c=1;c<=j;c++){
      System.out.print("*");
    }
     
   
    j+=2;
    
    System.out.print("\n");
            //define k variable for saving the new value of j which is unachnagble
    k=j-4;
      }else{

      //space is inceasing & column is decreasing here
        for(int space=row/2;space<r;space++){
        System.out.print(" ");
        }
        for(int c=1;c<=k;c++){
          System.out.print("*");
        }
        k-=2;
        System.out.print("\n");
        }  
      }
    }
}

Problem  #13:

Rhombus
Just draw the image of the above triangle once. And then, the opposite, once.
Sample input:

Sample input:
3
Sample output
1
123
12345
123
1

Solution:

import java.util.Scanner;
public class Task13{
  public static void main(String[] args){
    int n;
    Scanner sc = new Scanner(System.in);
    
    System.out.print("Input row");
    int row = sc.nextInt();
    row*=2;
    int j =1;
    int k=1;
    
    for(int r = 1 ;r<row;r++){
      if(r<=row/2){
      //while row is increasing space is decreasing
      for(int space = 1;space<=row/2-r;space++){
      System.out.print(" ");
      }
      for(int c=1;c<=j;c++){
      System.out.print(c);
    }
     
   
    j+=2;
    
    System.out.print("\n");
            //define k variable for saving the new value of j which is unachnagble
    k=j-4;
      }else{

      //space is inceasing & column is decreasing here
        for(int space=row/2;space<r;space++){
        System.out.print(" ");
        }
        for(int c=1;c<=k;c++){
          System.out.print(c);
        }
        k-=2;
        System.out.print("\n");
        }  
      }
    }
}

Problem  #14:

Hollow Rectangle
Display a rectangle of given length and width.

Sample input:
4

5
Sample output
*****
*      *
*      *
*****

Solution:

import java.util.Scanner;
public class Task14{
  public static void main(String[] args){
    int n;
    Scanner sc = new Scanner(System.in);
    
    System.out.print("Input row/length");
    int row = sc.nextInt();
    
    System.out.print("Int column/width");
    int col = sc.nextInt();

    
    for(int r = 1 ;r<=row;r++){
      for(int c=1;c<=col;c++){
        if(r==1|r==row|c==1|c==col){
          System.out.print("*");
        }else{
          System.out.print(" ");
        }
      }
      System.out.print("\n");
      }
    }
}

Problem  #15:

Hollow Rectangle
Display a rectangle of given length and width.

Sample input:
4

5
Sample output
12345
1       5
1       5
12345

Solution:

import java.util.Scanner;
public class Task15{
  public static void main(String[] args){
    int n;
    Scanner sc = new Scanner(System.in);
    
    System.out.print("Input row/length");
    int row = sc.nextInt();
    
    System.out.print("Int column/width");
    int col = sc.nextInt();

    
    for(int r = 1 ;r<=row;r++){
      for(int c=1;c<=col;c++){
        if(r==1|r==row|c==1|c==col){
          System.out.print(c);
        }else{
          System.out.print(" ");
        }
      }
      System.out.print("\n");
      }
    }
}

To be continued……