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Patterns: Java Program To Print Patterns Of Numbers And Stars

Patterns are most important for interview point of view. To understand pattern problem you know only the basic tactic of how to solve pattern problem. In Java, it becomes a little bit easier to code patterns problems.

pat11

In this article we discuss 20 basic pattern problem in java.

Java Program: To Check If A Number Is Prime In Java

Lets get start :)

John Academy

Patterns In Java

1. Left Triangle Star Pattern:

First, let us begin with the basic and the commonly asked pattern program in Java i.e This is the basic pattern in java to write its code . Their is only two loops are used one for row and another for column.

pat11

Let’s write the java code:


import java.util.*;
public class Main {

    public static void main(String[] args) {
        Scanner scn = new Scanner(System.in);

        // write ur code here
        int n = scn.nextInt();
        for (int i = 1; i <= n; i++){
            for(int j = 1; j <= i; j++){
                System.out.print("*\t");
            }
            System.out.println();
        }

    }
}

2. Downward Triangle Star Pattern:

pat21
import java.util.*;
public class Main {
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);

    // write ur code here
    int n = scn.nextInt();
    for (int i = n; i >= 1; i--){
        for(int j = i; j >= 1; j--){
            System.out.print("*\t");
        }
        System.out.println();
    }

}
}

3. Right Triangle Star Pattern:

pat31
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
int n = scn.nextInt();
// write ur code here    
int sp = n - 1;
    int st = 1;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= sp; j++){
            System.out.print("\t");
        }
        for(int k = 1;k <= st; k++){
            System.out.print("*\t");
        }
        System.out.println();
        sp--;
        st++;
    }
}
}

4. Right down Mirror Star Pattern:

pat41
import java.util.*;
public class Main {
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
    // write ur code here

    int sp = 0;
    int st = n;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= sp; j++){
            System.out.print("\t");
        }
        for(int k = 1;k <= st; k++){
            System.out.print("*\t");
        }
        System.out.println();
        sp++;
        st--;
    }
}
}

5.  Diamond Shape Pattern Program in Java:

pat51
import java.util.*;
public class Main {
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
    // write ur code here

    int sp = n / 2;
    int st = 1;
    for(int i = 1; i <= n; i++){
        for(int j = 1;j <= sp; j++){
            System.out.print("\t");
        }
        for(int k = 1;k <= st; k++){
            System.out.print("*\t");
        }
        if(i <= n / 2){
            sp--;
            st += 2;
        }
        else{
            sp++;
            st -= 2;
        }
        System.out.println();
    }
} }

6. Space Diamond:

pat61
import java.util.*;
public class Main {
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
    // write ur code here

    int tst = n + 1;
    int st = tst / 2;
    int sp = 1;
    for(int i = 1; i <= n; i++){
        // System.out.print(st + "," + sp);
        for(int j = 1; j <= st; j++){
            System.out.print("*\t");
        }
        for(int k = 1; k <= sp; k++){
            System.out.print("\t");
        }
        for(int j = 1; j <= st; j++){
            System.out.print("*\t");
        }
        if(i <= n / 2){
        st--;
        sp += 2;
    }
    else{
        st++;
        sp -= 2;
    }
    System.out.println();
    }

} }

7. Left-Diagonal Star Pattern:

pat71
import java.util.*;
public class Main {
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
    // write ur code here

    int sp = 0;
    for(int i = 1; i <= n; i++){
        for(int j = 0; j < sp; j++){
            System.out.print("\t");
        }
        System.out.print("*");
        System.out.println();
        sp++;
    }
}
}

8. Right-Diagonal Star Pattern:

pat81
import java.util.*;
public class Main {
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
    // write ur code here

    int sp = n - 1;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= sp; j++){
            System.out.print("\t");
        }
        System.out.print("*");
        System.out.println();
        sp--;
    }
}
}

9. Double-Diagonal Star Pattern:

pat91
import java.util.*;
public class Main {
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);

    // write ur code here
    int n = scn.nextInt();
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= n; j++){
            if(i+j == n + 1 || i == j){
                System.out.print("*\t");
            }
            else{
                System.out.print("\t");
            }
        }
        System.out.println();
    }

}
}

10. Diamond Star Pattern:

pat101
import java.util.*;
public class Main {
 public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
// write ur code here
 int n = scn.nextInt();
 int os = n / 2;
 int is = -1;
 for(int i = 1; i <= n; i++){
     for(int j = 1; j <= os; j++){
         System.out.print("\t");
     }
     System.out.print("*\t");
     for(int k = 1; k <= is; k++){
         System.out.print("\t");
     }
     if(i > 1 && i < n){
         System.out.print("*\t");
     }
     if(i <= n /2){
         os--;
         is += 2;
     }
     else{
         os++;
         is -= 2;
     }
     System.out.println();
 }
}
}

11. Simple Number Program:

pat111
import java.util.*;

public class Main{
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
    // write ur code here
    int var = 1;
    for(int i = 1; i <= n; i++){
        for(int j = 1;j <= i; j++){
            System.out.print(var + "\t");
            var++;
        }
        System.out.println();
    }
}
}

12. Fibonacci Number Pattern:

pat121
import java.util.*;

public class Main{
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
    // write ur code here
    int a = 0;
    int b = 1;
    int c;
    for(int i = 1; i <= n; i++){
        for(int j = 1;j <= i; j++){
            System.out.print(a + "\t");
            c = a + b;
            a = b;
            b = c;

        }
        System.out.println();
    }
}
}

13. Simple Number Pattern:

pat131
import java.util.*;

public class Main{
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
    // write ur code here

    for(int i = 0; i < n; i++){
        int icj = 1;
        for(int j = 0;j <= i; j++){
            System.out.print(icj + "\t");
            int icj1 = icj * (i - j) / (j + 1);
            icj = icj1;
        }
        System.out.println();
    }
}
}

14. Multiplication Number Pattern:

pat141
import java.util.*;

public class Main{
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
    // write ur code here

    for(int i = 1; i <= 10; i++){
        int v = n * i;
        System.out.println(n + " * " + i + " = " + v);
    }
}
}

15. Diamond Number Pattern:

pat151
import java.util.*;

public class Main{
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
    int sp = n / 2;
    int st = 1;
    int val = 1;
    // write ur code here

    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= sp; j++){
            System.out.print("\t");
        }
        int cval = val;
        for(int k = 1; k <= st; k++){
            System.out.print(cval + "\t");
            if (k <= st / 2){
                cval++;
            }
            else{
                cval--;
            }

        }
        if(i <= n /2){
            sp--;
            st += 2;
            val++;
        }
        else{
            sp++;
            st -= 2;
            val--;
        }

        System.out.println();
    }

}
}

16. Half-Space Diamond Number Pattern:

pat161
import java.util.*;

public class Main{

public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
     // write ur code here
     int st = 1;
     int sp = (2 * n) - 3;
     for(int i = 1; i <= n; i++){
         int val = 1;
         for(int j = 1; j <= st; j++){
             System.out.print(val + "\t");
             val++;
         }
         for(int k = 1; k <= sp; k++){
             System.out.print("\t");
         }
         if(i == n){
             st--;
             val--;
         }
         for(int l = 1; l <= st; l++){
             val--;
             System.out.print(val + "\t");
         }
         sp -= 2;
         st++;
         System.out.println();
     }

 }
}

17. Special Cut Diamond Star Pattern:

pat171
import java.util.*;

public class Main{
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);

    // write ur code here
    int n = scn.nextInt();
    int st = 1;
    int sp = n / 2;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= sp; j++){
            if(i == n / 2 + 1){
                System.out.print("*\t");
            }
            else{
            System.out.print("\t");
            }
        }

        for(int j = 1; j <= st; j++){
            System.out.print("*\t");
        }
        if(i <= n/2){
            st++;
        }
        else{
            st--;
        }
        System.out.println();
    }

}
}

18. Sandglass Star Pattern:

pat181


import java.util.*;

public class Main{

public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();
     // write ur code here
     int st = n;
     int sp = 0;
     for(int i = 1; i  <= n; i++){
         for(int j = 1; j  <= sp; j++){
             System.out.print("\t");
         }
         for(int j = 1; j <= st; j++){
             if(i > 1 && i  <= n / 2 && j > 1 && j < st){
                 System.out.print("\t");
             }
             else{
             System.out.print("*\t");
             }
         }
         for(int j = 1; j  <= sp; j++){
             System.out.print("\t");
         }
         if(i  <= n/2){
             sp++;
             st -= 2;
         }
         else{
             sp--;
             st +=2;
         }
         System.out.println();
     }

 }
}

19. Swastik Star Pattern:

pat191
import java.util.*;

public class Main{

public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt(); 
// write ur code here
 for(int i = 1; i <= n; i++){
     for(int j = 1; j <= n; j++){
         if(i == 1){
             if(j <= n /2 + 1 || j == n){
                 System.out.print("*\t"); }
             else{
                 System.out.print("\t"); }
         }
         else if(i <= n / 2){
             if(j == n /2 + 1 || j == n){
                 System.out.print("*\t");
             }
             else{
                 System.out.print("\t");
             }

         }
         else if(i == n / 2 + 1){
             System.out.print("*\t");
         }
         else if(i < n){
             if(j == n /2 + 1 || j == 1){
                 System.out.print("*\t");
             }
             else{
                 System.out.print("\t");
             }

         }
         else{
             if(j >= n /2 + 1 || j == 1){
                 System.out.print("*\t");
             }
             else{
                 System.out.print("\t");
             }
         }
     }
     System.out.println();
 }
}
}

20. W Star Pattern:

pat201
import java.util.*;

public class Main {
public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    // write ur code here
    int n = scn.nextInt();
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= n; j++){
            if(j == 1 || j == n){
                System.out.print("*\t");
            }
            else if(i > n / 2 && (i == j || i + j == n + 1)){
                System.out.print("*\t");
            }
            else{
                System.out.print("\t");
            }
        }
        System.out.println();
    }

}
}

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