Patterns Problems:

1. No of Rows === No of Columns ==5

    /* Pattern : N= 5
   
    * * * * *
    * * * * *
    * * * * *
    * * * * *
    * * * * *
   
    */
    class Main {
       static void pattern1(int N)
    {
        // This is the outer loop which will loop for the rows.
        for (int i = 0; i < N; i++)
        {
             // This is the inner loop which here, loops for the columns
            // as we have to print a rectangular pattern.
            for (int j = 0; j < N; j++)
            {
                System.out.print("* ");
            }
   
             // As soon as N stars are printed, we move to the
            // next row and give a line break otherwise all stars
            // would get printed in 1 line.
            System.out.println();
        }
    }
   
        public static void main(String[] args) {
   
            // Here, we have taken the value of N as 5.
            // We can also take input from the user.
            int N = 5;
            pattern1(N);
        }
    }
   

1. Right Angled triangle with increasing N and left aligned.

    /* Pattern : N= 5
   
    * 
    * * 
    * * * 
    * * * * 
    * * * * *
   
    */
    class pattern2 {
       static void pattern2(int N)
    {
        // This is the outer loop which will loop for the rows.
        for (int i = 1; i <= N; i++)
        {
             // This is the inner loop which here, loops for the columns
           // no. of columns = row number for each line here.
            for (int j = 1; j <= i; j++)
            {
                System.out.print("* ");
            }
   
             // As soon as N stars are printed, we move to the
            // next row and give a line break otherwise all stars
            // would get printed in 1 line.
            System.out.println();
        }
    }
   
        public static void main(String[] args) {
   
            // Here, we have taken the value of N as 5.
            // We can also take input from the user.
            int N = 5;
            pattern2(N);
        }
    }
   

2. Right angled left aligned triangle with numbers of column no.

    /* Pattern : N= 5
   
    1
    1 2
    1 2 3 
    1 2 3 4
    1 2 3 4 5
   
    */
    class pattern3 {
       static void pattern3(int N)
    {
        // This is the outer loop which will loop for the rows.
        for (int i = 1; i <= N; i++)
        {
             // This is the inner loop which loops for the columns
           // no. of columns = row number for each line here.
           // Here, we print numbers from 1 to the row number
           // instead of stars in each row.
           for (int j = 1; j <= i; j++)
            {
                System.out.print(j+" ");
            }
   
             // As soon as N stars are printed, we move to the
            // next row and give a line break otherwise all stars
            // would get printed in 1 line.
            System.out.println();
        }
    }
   
        public static void main(String[] args) {
   
            // Here, we have taken the value of N as 5.
            // We can also take input from the user.
            int N = 5;
            pattern3(N);
        }
    }
   

3. Right angled left aligned triangle with numbers of row no.

    /* Pattern : N= 5
   
    1
    2 2
    3 3 3
    4 4 4 4
    5 5 5 5 5
   
    */
    class pattern4 {
       static void pattern4(int N)
    {
        // This is the outer loop which will loop for the rows.
        for (int i = 1; i <= N; i++)
        {
           // This is the inner loop which loops for the columns
           // no. of columns = row number for each line here.
           // Here, we print numbers equal to the column number
           for (int j = 1; j <= i; j++)
            {
                System.out.print(i+" ");
            }
   
             // As soon as N stars are printed, we move to the
            // next row and give a line break otherwise all stars
            // would get printed in 1 line.
            System.out.println();
        }
    }
   
        public static void main(String[] args) {
   
            // Here, we have taken the value of N as 5.
            // We can also take input from the user.
            int N = 5;
            pattern4(N);
        }
    }
   

4. Right angled linverted eft aligned triangle

    /* Pattern : N= 5
   
    5 4 3 2 1 
    4 3 2 1 
    3 2 1 
    2 1 
    1
   
    */
    class pattern6 {
       static void pattern6(int N)
    {
        // This is the outer loop which will loop for the rows.
        for (int i = N; i >= 1; i--)
        {
           // This is the inner loop which loops for the columns
            // no. of columns = (N - row index) for each line here
            // as we have to print an inverted pyramid.
            // (N-j) will give us the numbers in a row starting from 1 to N-i.
             for (int j = i; j >= 1; j--)
            {
                System.out.print(j+" ");
            }
   
             // As soon as N stars are printed, we move to the
            // next row and give a line break otherwise all stars
            // would get printed in 1 line.
            System.out.println();
        }
    }
   
        public static void main(String[] args) {
   
            // Here, we have taken the value of N as 5.
            // We can also take input from the user.
            int N = 5;
            pattern6(N);
        }
    }
   

5. pattern 7

    /* Pattern : N= 5
   
    1 2 3 4 5
    1 2 3 4
    1 2 3 
    1 2 
    1
   
    */
    class pattern7 {
       static void pattern7(int N)
    {
        // This is the outer loop which will loop for the rows.
        for (int i = N; i >=1 ; i--)
        {
             // This is the inner loop which loops for the columns
            // no. of columns = (N - row index) for each line here
            // as we have to print an inverted pyramid.
            // (N-j) will give us the numbers in a row starting from 1 to N-i.
            for (int j = 1; j<= i; j++)
            {
                System.out.print(j+" ");
            }
   
             // As soon as N stars are printed, we move to the
            // next row and give a line break otherwise all stars
            // would get printed in 1 line.
            System.out.println();
        }
    }
   
        public static void main(String[] args) {
   
            // Here, we have taken the value of N as 5.
            // We can also take input from the user.
            int N = 5;
            pattern7(N);
        }
    }