Program to print the pattern ‘G’
In this article, we will learn how to print the pattern G using stars and white-spaces. Given a number n, we will write a program to print the pattern G over n lines or rows.
Examples:
Input : 7
Output :
***
*
*
* ***
* *
* *
***
Input : 9
Output :
*****
*
*
*
* ***
* *
* *
* *
*****
In this program, we have used the simple logic of iteration over lines to create the pattern G. Please look at the image below which represents the pattern G in the form of a 2-d matrix, where mat[i][j] = ‘ij’:
If we try to analyze this picture with a (row, column) matrix and the circles represent the position of stars in the pattern G, we will learn the steps. Here we are performing the operations column-wise. So for the first line of stars, we set the first if condition, where the row position with 0 and (n-1) won’t get the stars and all other rows from 1 to (n-1), will get the stars. Similarly, for the second, third and fourth column we want stars at the position row = 0 and row = (n-1). The other steps are self-explanatory and can be understood from the position of rows and columns in the diagram.
Below is the implementation of above idea:
C++
#include <iostream>
using namespace std;
void pattern( int line)
{
int i, j;
for (i = 0; i < line; i++)
{
for (j = 0; j < line; j++)
{
if ((j == 1 && i != 0 && i != line - 1) ||
((i == 0 || i == line - 1) && j > 1 &&
j < line - 2) || (i == ((line - 1) / 2) &&
j > 2 && j < line - 1) || (j == line - 2 &&
i != 0 && i >= ((line - 1) / 2) && i != line - 1))
printf ( "*" );
else
printf ( " " );
}
printf ( "\n" );
}
}
int main()
{
int line = 7;
pattern(line);
return 0;
}
|
Java
import java.io.*;
class GFG {
static void pattern( int line)
{
int i, j;
for (i = 0 ; i < line; i++)
{
for (j = 0 ; j < line; j++)
{
if ((j == 1 && i != 0 && i != line - 1 ) ||
((i == 0 || i == line - 1 ) && j > 1 &&
j < line - 2 ) || (i == ((line - 1 ) / 2 ) &&
j > 2 && j < line - 1 ) || (j == line - 2 &&
i != 0 && i >= ((line - 1 ) / 2 ) && i != line - 1 ))
System.out.print( "*" );
else
System.out.print( " " );
}
System.out.println();
}
}
public static void main (String[] args)
{
int line = 7 ;
pattern(line);
}
}
|
Python
def Pattern(line):
pat = ""
for i in range ( 0 ,line):
for j in range ( 0 ,line):
if ((j = = 1 and i ! = 0 and i ! = line - 1 ) or ((i = = 0 or
i = = line - 1 ) and j > 1 and j < line - 2 ) or (i = = ((line - 1 ) / 2 )
and j > line - 5 and j < line - 1 ) or (j = = line - 2 and
i ! = 0 and i ! = line - 1 and i > = ((line - 1 ) / 2 ))):
pat = pat + "*"
else :
pat = pat + " "
pat = pat + "\n"
return pat
line = 7
print (Pattern(line))
|
C#
using System;
class GFG {
static void pattern( int line)
{
int i, j;
for (i = 0; i < line; i++)
{
for (j = 0; j < line; j++)
{
if ((j == 1 && i != 0 && i != line - 1) ||
((i == 0 || i == line - 1) && j > 1 &&
j < line - 2) || (i == ((line - 1) / 2) &&
j > 2 && j < line - 1) || (j == line - 2 &&
i != 0 && i >= ((line - 1) / 2) && i != line - 1))
Console.Write( "*" );
else
Console.Write( " " );
}
Console.WriteLine();
}
}
public static void Main ()
{
int line = 7;
pattern(line);
}
}
|
PHP
<?php
function Pattern( $line ){
for ( $i =0; $i < $line ; $i ++)
{
for ( $j =0; $j <= $line ; $j ++)
{
if (( $j == 1 and $i != 0 and $i != $line -1) or (( $i == 0 or
$i == $line -1) and $j > 1 and $j < $line -2) or ( $i == (( $line -1)/2)
and $j > 2 and $j < $line -1) or ( $j == $line -2 and
$i != 0 and $i >=(( $line -1)/2) and $i != $line -1))
echo "*" ;
else
echo " " ;
}
echo "\n" ;
}
}
$line = 7;
Pattern( $line )
?>
|
Javascript
<script>
function pattern(line) {
var i, j;
for (i = 0; i < line; i++) {
for (j = 0; j < line; j++) {
if (
(j == 1 && i != 0 && i != line - 1) ||
((i == 0 || i == line - 1) && j > 1 && j < line - 2) ||
(i == (line - 1) / 2 && j > 2 && j < line - 1) ||
(j == line - 2 && i != 0 && i >= (line - 1) / 2 && i != line - 1)
)
document.write( "*" );
else document.write( " " );
}
document.write( "<br>" );
}
}
var line = 7;
pattern(line);
</script>
|
Output:
***
*
*
* ***
* *
* *
***
Time Complexity: O(n2), where n represents the given input.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
Last Updated :
20 Feb, 2023
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