Program to print right and left arrow patterns

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Write to program to print the right arrow pattern and the left arrow pattern formed of stars. Input is an odd number n which represents height and width of pattern to be printed.
Examples:

Input : n = 9
Output :
    *
     *               
      *  
       *
*********
       *
      *
     *
    *


    *
   *
  *
 *
*********
 * 
  *
   *
    *


Input : n = 7
Output :
   *
    *
     *
*******
     *
    *
   *


   *
  *
 *
*******
 *
  *
   *

C++

// C++ program to print Pyramid pattern 
#include <iostream> 
using namespace std; 
  
// function to print right arrow pattern 
void rightpattern(int n) 
{ 
    // for printing upper portion 
    int c1 = (n - 1) / 2; 
  
    // for printing lower portion 
    int c2 = 3 * n / 2 - 1; 
  
    for (int i = 0; i < n; i++) { 
        for (int j = 0; j < n; j++) { 
  
            // checking conditions to print right arrow 
            if (j - i == c1 || i + j == c2 || i == c1) 
                cout << "*"; 
  
            // otherwise print space 
            else
                cout << " "; 
        } 
        // for jumping to next line 
        cout << "\n"; 
    } 
} 
  
// function to print left arrow pattern 
void leftpattern(int n) 
{ 
    char s = ' '; 
    char st = '*'; 
  
    // for printing upper part 
    for (int i = (n - 1) / 2; i > 0; i--) 
        cout << string(i, s) << st << endl; 
  
    // for printing middle part 
    for (int i = 0; i < n; i++) 
        cout << "*"; 
    cout << endl; 
  
    // for printing lower part 
    for (int i = 1; i <= (n - 1) / 2; i++) 
        cout << string(i, s) << st << endl; 
    cout << endl; 
} 
  
// Driver program 
int main() 
{ 
    int n = 9; // Must be odd 
  
    // function calling to print right arrow 
    rightpattern(n); 
  
    cout << endl  << endl; 
  
    // function calling to print left arrow 
    leftpattern(n); 
  
    return 0; 
} 

Java

// Java program to print Pyramid pattern  
class GFG  
{ 
  
// function to print right arrow pattern  
static void rightpattern(int n) 
{ 
    // for printing upper portion  
    int c1 = (n - 1) / 2; 
  
    // for printing lower portion  
    int c2 = 3 * n / 2 - 1; 
  
    for (int i = 0; i < n; i++)  
    { 
        for (int j = 0; j < n; j++)  
        { 
  
            // checking conditions to print 
            // right arrow  
            if (j - i == c1 ||  
                i + j == c2 || i == c1)  
            { 
                System.out.print("*"); 
            } // otherwise print space  
            else 
            { 
                System.out.print(" "); 
            } 
        } 
        // for jumping to next line  
        System.out.print("\n"); 
    } 
} 
  
static void string(int n)  
{ 
    for (int i = n; i > 0; i--)  
    { 
        System.out.print(" "); 
    } 
} 
  
// function to print left arrow pattern  
static void leftpattern(int n)  
{ 
    char s = ' '; 
    char st = '*'; 
  
    // for printing upper part  
    for (int i = (n - 1) / 2; i > 0; i--)  
    { 
        string(i); 
        System.out.println(st); 
    } 
      
    // for printing middle part  
    for (int i = 0; i < n; i++)  
    { 
        System.out.print("*"); 
    } 
    System.out.println(); 
  
    // for printing lower part  
    for (int i = 1; i <= (n - 1) / 2; i++)  
    { 
        string(i); 
        System.out.println(st); 
    } 
    System.out.println(); 
} 
  
// Driver Code 
public static void main(String args[]) 
{ 
    int n = 9; // Must be odd  
  
    // function calling to print  
    // right arrow  
    rightpattern(n); 
  
    System.out.println("\n"); 
  
    // function calling to print  
    // left arrow  
    leftpattern(n); 
} 
} 
  
// This code is contributed  
// by PrinciRaj1992  

Python3

# Python3 program to print Pyramid pattern 
  
# function to print right arrow pattern 
def rightpattern(n): 
      
    # for printing upper portion 
    c1 = (n - 1) // 2; 
  
    # for printing lower portion 
    c2 = 3 * n // 2 - 1; 
  
    for i in range(n): 
  
        for j in range(n): 
  
            # checking conditions to print 
            # right arrow 
            if (j - i == c1 or
                i + j == c2 or i == c1): 
  
                print("*", end = ""); 
                  
            # otherwise print space 
            else: 
  
                print(" ", end = ""); 
  
        # for jumping to next line 
        print(); 
  
def string(n): 
  
    for i in range(n): 
        print(" ", end = ""); 
  
# function to print left arrow pattern 
def leftpattern(n): 
  
    s = ' '; 
    st = '*'; 
  
    # for printing upper part 
    for i in range((n - 1) // 2, 0, -1): 
        string(i); 
        print(st); 
  
    # for printing middle part 
    for i in range(n): 
        print("*", end = ""); 
  
    print(); 
  
    # for printing lower part 
    for i in range(1, ((n - 1) // 2) + 1): 
        string(i); 
        print(st); 
  
    print(); 
  
# Driver Code 
if __name__ == '__main__': 
    n = 9; # Must be odd 
  
    # function calling to print 
    # right arrow 
    rightpattern(n); 
  
    print(""); 
  
    # function calling to print 
    # left arrow 
    leftpattern(n); 
  
# This code is contributed by PrinciRaj1992 

C#

// C# program to print Pyramid pattern  
using System; 
  
class GFG  
{ 
  
// function to print right arrow pattern  
static void rightpattern(int n) 
{ 
    // for printing upper portion  
    int c1 = (n - 1) / 2; 
  
    // for printing lower portion  
    int c2 = 3 * n / 2 - 1; 
  
    for (int i = 0; i < n; i++)  
    { 
        for (int j = 0; j < n; j++)  
        { 
  
            // checking conditions to print 
            // right arrow  
            if (j - i == c1 ||  
                i + j == c2 || i == c1)  
            { 
                Console.Write("*"); 
            } // otherwise print space  
            else
            { 
                Console.Write(" "); 
            } 
        } 
        // for jumping to next line  
        Console.Write("\n"); 
    } 
} 
  
static void String(int n)  
{ 
    for (int i = n; i > 0; i--)  
    { 
        Console.Write(" "); 
    } 
} 
  
// function to print left arrow pattern  
static void leftpattern(int n)  
{ 
    char s = ' '; 
    char st = '*'; 
  
    // for printing upper part  
    for (int i = (n - 1) / 2; i > 0; i--)  
    { 
        String(i); 
        Console.WriteLine(st); 
    } 
      
    // for printing middle part  
    for (int i = 0; i < n; i++)  
    { 
        Console.Write("*"); 
    } 
    Console.WriteLine(); 
  
    // for printing lower part  
    for (int i = 1; i <= (n - 1) / 2; i++)  
    { 
        String(i); 
        Console.WriteLine(st); 
    } 
    Console.WriteLine(); 
} 
  
// Driver Code 
public static void Main() 
{ 
    int n = 9; // Must be odd  
  
    // function calling to print  
    // right arrow  
    rightpattern(n); 
  
    Console.WriteLine("\n"); 
  
    // function calling to print  
    // left arrow  
    leftpattern(n); 
} 
} 
  
// This code is contributed  
// by Akanksha Rai 

PHP

<?php 
  
// function to print right arrow pattern 
function rightpattern($n) 
{ 
      
    // for printing upper portion 
    $c1 = ($n - 1) / 2; 
  
    // for printing lower portion 
    $c2 = floor(3 * $n / 2 - 1); 
  
    for ($i = 0; $i < $n; $i++) 
    { 
        for ($j = 0; $j < $n; $j++)  
        { 
  
            // checking conditions to  
            // print right arrow 
            if (($j - $i) == $c1 ||  
                ($i + $j) == $c2 ||  
                 $i == $c1) 
                echo "*"; 
  
            // otherwise print space 
            else
                echo " "; 
        } 
          
        // for jumping to next line 
        echo "\n"; 
    } 
} 
  
// function to print left arrow pattern 
function leftpattern($n) 
{ 
    $s = ' '; 
    $st = '*'; 
  
    // for printing upper part 
    for ($i = ($n - 1) / 2; $i > 0; $i--) 
    { 
    for($j = 0; $j < $i; $j++) 
        echo " "; 
    echo $st."\n"; 
    } 
      
    // for printing middle part 
    for ($i = 0; $i < $n; $i++) 
        echo "*"; 
    echo "\n"; 
  
    // for printing lower part 
    for ($i = 1; $i <= ($n - 1) / 2; $i++) 
    { 
            for($j = 0; $j < $i; $j++) 
        echo " "; 
    echo $st."\n"; 
    } 
    echo "\n"; 
} 
  
    // Driver Code 
    $n = 9; // Must be odd 
  
    // function calling to  
    // print right arrow 
    rightpattern($n); 
  
    echo "\n\n"; 
  
    // function calling to  
    // print left arrow 
    leftpattern($n); 
  
  
// This code is contributed by mits  
  
?> 

Javascript

<script> 
  
      // function to print right arrow pattern 
      function rightpattern(n) { 
        // for printing upper portion 
        var c1 = (n - 1) / 2; 
  
        // for printing lower portion 
        var c2 = Math.floor((3 * n) / 2 - 1); 
  
        for (var i = 0; i < n; i++) { 
          for (var j = 0; j < n; j++) { 
            // checking conditions to 
            // print right arrow 
            if (j - i === c1 || i + j === c2  
            || i === c1)  
            document.write("*"); 
            // otherwise print space 
            else 
            document.write("  "); 
          } 
  
          // for jumping to next line 
          document.write("<br>"); 
        } 
      } 
  
      // function to print left  
      // arrow pattern 
      function leftpattern(n) { 
        var s = " "; 
        var st = "*"; 
  
        // for printing upper part 
        for (var i = (n - 1) / 2; i > 0; i--) { 
          for (var j = 0; j < i; j++)  
          document.write("  "); 
          document.write(st + "<br>"); 
        } 
  
        // for printing middle part 
        for (var i = 0; i < n; i++)  
        document.write("*"); 
        document.write("<br>"); 
  
        // for printing lower part 
        for (var i = 1; i <= (n - 1) / 2; i++) 
        { 
          for (var j = 0; j < i; j++)  
          document.write("  "); 
          document.write(st + "<br>"); 
        } 
        document.write("<br>"); 
      } 
  
      // Driver Code 
      var n = 9; // Must be odd 
      // function calling to 
      // print right arrow 
      rightpattern(n); 
      document.write("<br><br>"); 
      // function calling to 
      // print left arrow 
      leftpattern(n); 
        
</script>

Output:

    *
     *               
      *  
       *
*********
       *
      *
     *
    *


    *
   *
  *
 *
*********
 *
  *
   *
    *

Time Complexity: O(n^2)

Auxiliary Space: O(1) because it is using constant space for variables

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