Write a Program to Print Square Using * Character

By | June 7, 2021

Printing patterns using * is one of the most common interview questions. In this article, we will learn how to print a hollow square bracket in a console using C, C++, and Python programming languages.

The Syntax for all these three programming languages is different but the algorithm and logic would remain the same to print the square bracket.

Vamware

Algorithm 

  • Create a nested loop from 0 to n where n is the length and width of the square.
  • Inside the nested loop print * if the outer loop value is 0 or n-1, or the inner loop value is 0 or n-1.
  • For all the other values print the empty space ” “.
  • With this, the star will be printed only for the outer parameter of the square.

Print Square Pattern in C

#include<stdio.h>

int main()
{
	int i, j, n;
	//input the width or height of the square
	printf("Enter the Height of Square: ");
	scanf("%d", &n);
	
	//create a nested loop
	//from 0 to n
	for(i =0; i<n; i++)
	{
		for(j=0;j<n;j++)
		{	
			//print * if the value of 
			//outer or inner loop value is 0 or n-1
			if(i==0||i==n-1||j==0||j==n-1)
			{
				printf("*");
			}
			else
			//else print empty spaces
			{
				printf(" ");
			}
		}
		printf("\n");
	}
	
	return 0;
}

Output

Enter the Height of Square: 12
************
*          *
*          *
*          *
*          *
*          *
*          *
*          *
*          *
*          *
*          *
************

Print Square Pattern in C++

#include <iostream>
using namespace std;
 
int main()
{	
	int i, j, n;
	
	//input the width or height of the square
	cout<<"Enter the Height of Square: "; cin>>n;
	
	//create a nested loop
	//from 0 to n
	for(i =0; i<n; i++)
	{
		for(j=0;j<n;j++)
		{	
			//print * if the value of 
			//outer or inner loop value is 0 or n-1
			if(i==0||i==n-1||j==0||j==n-1)
			{
				cout<<"*";
			}
			else
			//else print empty spaces
			{
				cout<<" ";
			}
		}
		cout<<"\n";
	}
	
	return 0;
}

Output

Enter the Height of Square: 13
*************
*           *
*           *
*           *
*           *
*           *
*           *
*           *
*           *
*           *
*           *
*           *
*************

Print Square Pattern in Python

n = int(input("Enter the Height of Square: "))

# create a nested loop
# from 0 to n

for i in range(n):
    for j in range(n):
        #print * if the value of 
        #outer or inner loop value is 0 or n-1
        if (i==0 or i==n-1 or j==0 or j==n-1):
            print("*", end="")
        else:
            # else print empty spaces
            print(" ", end ="")
    print()

Output

Enter the Height of Square: 14
**************
*            *
*            *
*            *
*            *
*            *
*            *
*            *
*            *
*            *
*            *
*            *
*            *
**************

Complexity Analysis

Time Complexity: O(N^2), is the time complexity of the above program because we are using a nested loop.

Space Complexity: O(1).

Wrapping Up!

In this article, we learn how to write a program in C, C++, and Python to print a hollow square box in a console using * character.  The algorithm for this program is very simple we just need to print the * character for all the points where i or j is either 0 or n-1, and for the rest of the points, we just print blank space.

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