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Print L pattern

In this article, we will discuss the problem of printing an L pattern using stars (*) in the C programming language. We will provide a detailed explanation of the problem, along with a suitable example and the algorithm to solve it. Additionally, we will include pseudocode and analyze the time complexity of the code.

Problem Statement

The task is to write a program that prints the L pattern using stars. The pattern should be printed based on the given height. The L pattern consists of a vertical line of stars followed by a horizontal line of stars at the bottom. The spaces are filled with empty spaces. For example, if the height is 6, the pattern would be printed as follows: 

*
*
*
*
*
* * *

Explanation with Example

Let's take the example of a height of 6 to understand the pattern.

To print the pattern, we iterate through each row from 0 to height-1. For each row, if it is the last row (height-1), we print a horizontal line of stars. Otherwise, we print a single star and move to the next line. This process continues until we have printed the required number of rows. In the given example, when the height is 6, the first five rows are printed with a single star in each row. Finally, the last row is printed with a horizontal line of stars. This creates the L pattern.

Algorithm

Here is the algorithm to solve the problem:

  1. Define a function named print_star that takes an integer size as a parameter.
  2. Initialize a counter variable to 0.
  3. Iterate through the loop until the counter is less than size:
    • If the counter is even, print a star.
    • Otherwise, print a space.
  4. Define a function named print_space that takes an integer size as a parameter.
  5. Initialize a counter variable to 0.
  6. Iterate through the loop until the counter is less than size:
    • Print a space.
  7. Define a function named print_l that takes an integer height as a parameter.
  8. If height is less than or equal to 2, return from the function.
  9. Print the height value and a newline character to indicate the start of the pattern.
  10. Iterate through the loop from 0 to height-1:
    • If the current row is the last row (height-1), call the print_star function with the height parameter.
    • Otherwise, print a single star.
    • Print a newline character to move to the next line.
  11. In the main function:
    • Call the print_l function with different height values to test the code.

Pseudocode

Here is the pseudocode for the given problem:

function print_star(size):
    counter = 0
    while counter < size:
        if counter is even:
            print "*"
        else:
            print " "
        increment counter

function print_space(size):
    counter = 0
    while counter < size:
        print " "
        increment counter

function print_l(height):
    if height <= 2:
        return
    print "Height: ", height
    for i from 0 to height-1:
        if i is height-1:
            call print_star function with height parameter
        else:
            print "*"
        print newline

function main():
    call print_l function with different height values

call main function

Code Solution

Here given code implementation process.

//C Program 
//Print L star pattern
#include <stdio.h>

//Include star of given size
void print_star(int size)
{
	int counter = 0;
	for (counter = 0; counter < size; counter++)
	{
		if (counter % 2 == 0)
		{
			//Add Star
			printf("*");
		}
		else
		{
			//Add Space
			printf(" ");
		}
	}
}
//Display space of given size
void print_space(int size)
{
	int counter = 0;
	for (counter = 0; counter < size; counter++)
	{
		//Add space
		printf(" ");
	}
}
//Print 'L' star pattern of given height
void print_l(int height)
{
	if (height <= 2)
	{
		return;
	}
	printf("\nHeight : %d  \n\n", height);
	for (int i = 0; i < height; ++i)
	{
		if (i == height - 1)
		{
			//last row of star
			print_star(height);
		}
		else
		{
			printf("*");
		}
		printf("\n");
	}
}
int main()
{
	//Simple test
	print_l(6);
	print_l(9);
	print_l(3);
	print_l(8);
	return 0;
}

Output

Height : 6

*
*
*
*
*
* * *

Height : 9

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

Height : 3

*
*
* *

Height : 8

*
*
*
*
*
*
*
* * * *
/*
  Java Program
  Print L star pattern
*/
class MyPattern
{
	//Include star of given size
	public void print_star(int size)
	{
		int counter = 0;
		for (counter = 0; counter < size; counter++)
		{
			if (counter % 2 == 0)
			{
				//Add Star
				System.out.print("*");
			}
			else
			{
				//Add Space
				System.out.print(" ");
			}
		}
	}
	//Display space of given size
	public void print_space(int size)
	{
		int counter = 0;
		for (counter = 0; counter < size; counter++)
		{
			//Add space
			System.out.print(" ");
		}
	}
	//Print 'L' star pattern of given height
	public void print_l(int height)
	{
		if (height <= 2)
		{
			return;
		}
		System.out.print("\nHeight : " + height + " \n\n");
		for (int i = 0; i < height; ++i)
		{
			if (i == height - 1)
			{
				//last row of star
				print_star(height);
			}
			else
			{
				System.out.print("*");
			}
			System.out.print("\n");
		}
	}
	public static void main(String[] args)
	{
		MyPattern obj = new MyPattern();
		//Simple test
		obj.print_l(6);
		obj.print_l(9);
		obj.print_l(3);
		obj.print_l(8);
	}
}

Output

Height : 6

*
*
*
*
*
* * *

Height : 9

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

Height : 3

*
*
* *

Height : 8

*
*
*
*
*
*
*
* * * *
/*
  C++ Program
  Print L star pattern
*/
#include<iostream>

using namespace std;
class MyPattern
{
	public:
		//Include star of given size
		void print_star(int size)
		{
			int counter = 0;
			for (counter = 0; counter < size; counter++)
			{
				if (counter % 2 == 0)
				{
					cout << "*";
				}
				else
				{
					cout << " ";
				}
			}
		}
	//Display space of given size
	void print_space(int size)
	{
		int counter = 0;
		for (counter = 0; counter < size; counter++)
		{
			cout << " ";
		}
	}
	//Print 'L' star pattern of given height
	void print_l(int height)
	{
		if (height <= 2)
		{
			return;
		}
		cout << "\nHeight : " << height << " \n\n";
		for (int i = 0; i < height; ++i)
		{
			if (i == height - 1)
			{
				//last row of star
				this->print_star(height);
			}
			else
			{
				cout << "*";
			}
			cout << "\n";
		}
	}
};
int main()
{
	MyPattern obj = MyPattern();
	//Simple test
	obj.print_l(6);
	obj.print_l(9);
	obj.print_l(3);
	obj.print_l(8);
	return 0;
}

Output

Height : 6

*
*
*
*
*
* * *

Height : 9

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

Height : 3

*
*
* *

Height : 8

*
*
*
*
*
*
*
* * * *
/*
  C# Program
  Print L star pattern
*/
using System;
class MyPattern
{
	//Include star of given size
	public void print_star(int size)
	{
		int counter = 0;
		for (counter = 0; counter < size; counter++)
		{
			if (counter % 2 == 0)
			{
				Console.Write("*");
			}
			else
			{
				Console.Write(" ");
			}
		}
	}
	//Display space of given size
	public void print_space(int size)
	{
		int counter = 0;
		for (counter = 0; counter < size; counter++)
		{
			Console.Write(" ");
		}
	}
	//Print 'L' star pattern of given height
	public void print_l(int height)
	{
		if (height <= 2)
		{
			return;
		}
		Console.Write("\nHeight : " + height + " \n\n");
		for (int i = 0; i < height; i++)
		{
			if (i == height - 1)
			{
				//last row of star
				print_star(height);
			}
			else
			{
				Console.Write("*");
			}
			Console.Write("\n");
		}
	}
	public static void Main(String[] args)
	{
		MyPattern obj = new MyPattern();
		//Simple test
		obj.print_l(6);
		obj.print_l(9);
		obj.print_l(3);
		obj.print_l(8);
	}
}

Output

Height : 6

*
*
*
*
*
* * *

Height : 9

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

Height : 3

*
*
* *

Height : 8

*
*
*
*
*
*
*
* * * *
<?php
/*
  Php Program
  Print L star pattern
*/
class MyPattern
{
	//Include star of given size
	function print_star($size)
	{
		$counter = 0;
		for ($counter = 0; $counter < $size; $counter++)
		{
			if ($counter % 2 == 0)
			{
				echo "*";
			}
			else
			{
				echo " ";
			}
		}
	}
	//Display space of given size
	function print_space($size)
	{
		$counter = 0;
		for ($counter = 0; $counter < $size; $counter++)
		{
			echo " ";
		}
	}
	//Print 'L' star pattern of given height
	function print_l($height)
	{
		if ($height <= 2)
		{
			return;
		}
		echo "\nHeight : ". $height ." \n\n";
		for ($i = 0; $i < $height; ++$i)
		{
			if ($i == $height - 1)
			{
				//last row of star
				$this->print_star($height);
			}
			else
			{
				echo "*";
			}
			echo "\n";
		}
	}
}

function main()
{
	$obj = new MyPattern();
	//Simple test
	$obj->print_l(6);
	$obj->print_l(9);
	$obj->print_l(3);
	$obj->print_l(8);
}
main();

Output

Height : 6

*
*
*
*
*
* * *

Height : 9

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

Height : 3

*
*
* *

Height : 8

*
*
*
*
*
*
*
* * * *
/*
  Node Js Program
  Print L star pattern
*/
class MyPattern
{
	//Include star of given size
	print_star(size)
	{
		var counter = 0;
		for (counter = 0; counter < size; counter++)
		{
			if (counter % 2 == 0)
			{
				process.stdout.write("*");
			}
			else
			{
				process.stdout.write(" ");
			}
		}
	}
	//Display space of given size
	print_space(size)
	{
		var counter = 0;
		for (counter = 0; counter < size; counter++)
		{
			process.stdout.write(" ");
		}
	}
	//Print 'L' star pattern of given height
	print_l(height)
	{
		if (height <= 2)
		{
			return;
		}
		process.stdout.write("\nHeight : " + height + " \n\n");
		for (var i = 0; i < height; ++i)
		{
			if (i == height - 1)
			{
				//last row of star
				this.print_star(height);
			}
			else
			{
				process.stdout.write("*");
			}
			process.stdout.write("\n");
		}
	}
}

function main()
{
	var obj = new MyPattern();
	//Simple test
	obj.print_l(6);
	obj.print_l(9);
	obj.print_l(3);
	obj.print_l(8);
}
main();

Output

Height : 6

*
*
*
*
*
* * *

Height : 9

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

Height : 3

*
*
* *

Height : 8

*
*
*
*
*
*
*
* * * *
#   Python 3 Program
#   Print L star pattern

class MyPattern :
	# Include star of given size
	def print_star(self, size) :
		counter = 0
		while (counter < size) :
			if (counter % 2 == 0) :
				print("*", end = "")
			else :
				print(" ", end = "")
			
			counter += 1
		
	
	# Display space of given size
	def print_space(self, size) :
		counter = 0
		while (counter < size) :
			print(" ", end = "")
			counter += 1
		
	
	# Print 'L' star pattern of given height
	def print_l(self, height) :
		if (height <= 2) :
			return
		
		print("\nHeight : ", height ," \n\n", end = "")
		i = 0
		while (i < height) :
			if (i == height - 1) :
				# last row of star
				self.print_star(height)
			else :
				print("*", end = "")
			
			print("\n", end = "")
			i += 1
		
	

def main() :
	obj = MyPattern()
	# Simple test
	obj.print_l(6)
	obj.print_l(9)
	obj.print_l(3)
	obj.print_l(8)

if __name__ == "__main__": main()

Output

Height :  6

*
*
*
*
*
* * *

Height :  9

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

Height :  3

*
*
* *

Height :  8

*
*
*
*
*
*
*
* * * *
#   Ruby Program
#   Print L star pattern

class MyPattern

	# Include star of given size
	def print_star(size)
	
		counter = 0
		while (counter < size)
		
			if (counter % 2 == 0)
			
				# Add Star
				print("*")
			else
			
				# Add Space
				print(" ")
			end
			counter += 1
		end
	end
	# Display space of given size
	def print_space(size)
	
		counter = 0
		while (counter < size)
		
			# Add space
			print(" ")
			counter += 1
		end
	end
	# Print 'L' star pattern of given height
	def print_l(height)
	
		if (height <= 2)
		
			return
		end
		print("\nHeight : ", height ," \n\n")
		i = 0
		while (i < height)
		
			if (i == height - 1)
			
				# last row of star
				self.print_star(height)
			else
			
				print("*")
			end
			print("\n")
			i += 1
		end
	end
end
def main()

	obj = MyPattern.new()
	# Simple test
	obj.print_l(6)
	obj.print_l(9)
	obj.print_l(3)
	obj.print_l(8)
end
main()

Output

Height : 6 

*
*
*
*
*
* * * 

Height : 9 

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

Height : 3 

*
*
* *

Height : 8 

*
*
*
*
*
*
*
* * * * 

/*
  Scala Program
  Print L star pattern
*/
class MyPattern
{
	//Include star of given size
	def print_star(size: Int): Unit = {
		var counter: Int = 0;
		while (counter < size)
		{
			if (counter % 2 == 0)
			{
				//Add Star
				print("*");
			}
			else
			{
				//Add Space
				print(" ");
			}
			counter += 1;
		}
	}
	//Display space of given size
	def print_space(size: Int): Unit = {
		var counter: Int = 0;
		while (counter < size)
		{
			//Add space
			print(" ");
			counter += 1;
		}
	}
	//Print 'L' star pattern of given height
	def print_l(height: Int): Unit = {
		if (height <= 2)
		{
			return;
		}
		print("\nHeight : " + height + " \n\n");
		var i: Int = 0;
		while (i < height)
		{
			if (i == height - 1)
			{
				//last row of star
				print_star(height);
			}
			else
			{
				print("*");
			}
			print("\n");
			i += 1;
		}
	}
}
object Main
{
	def main(args: Array[String]): Unit = {
		var obj: MyPattern = new MyPattern();
		//Simple test
		obj.print_l(6);
		obj.print_l(9);
		obj.print_l(3);
		obj.print_l(8);
	}
}

Output

Height : 6

*
*
*
*
*
* * *

Height : 9

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

Height : 3

*
*
* *

Height : 8

*
*
*
*
*
*
*
* * * *
/*
  Swift Program
  Print L star pattern
*/
class MyPattern
{
	//Include star of given size
	func print_star(_ size: Int)
	{
		var counter: Int = 0;
		while (counter < size)
		{
			if (counter % 2 == 0)
			{
				print("*", terminator: "");
			}
			else
			{
				print(" ", terminator: "");
			}
			counter += 1;
		}
	}
	//Display space of given size
	func print_space(_ size: Int)
	{
		var counter: Int = 0;
		while (counter < size)
		{
			print(" ", terminator: "");
			counter += 1;
		}
	}
	//Print "L" star pattern of given height
	func print_l(_ height: Int)
	{
		if (height <= 2)
		{
			return;
		}
		print("\nHeight : ", height ," \n\n", terminator: "");
		var i: Int = 0;
		while (i < height)
		{
			if (i == height - 1)
			{
				//last row of star
				self.print_star(height);
			}
			else
			{
				print("*", terminator: "");
			}
			print("\n", terminator: "");
			i += 1;
		}
	}
}
func main()
{
	let obj: MyPattern = MyPattern();
	//Simple test
	obj.print_l(6);
	obj.print_l(9);
	obj.print_l(3);
	obj.print_l(8);
}
main();

Output

Height :  6

*
*
*
*
*
* * *

Height :  9

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

Height :  3

*
*
* *

Height :  8

*
*
*
*
*
*
*
* * * *

Time Complexity

The time complexity of the code depends on the height parameter. The print_l function iterates through each row from 0 to height-1. Within each iteration, the print_star function is called once. Hence, the time complexity can be approximated to O(height).

Last updated on by Kalkicode




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