Given the number of lines as N, the task is to form the given hollow Triangle pattern.
Examples:
Input: N = 6 Output: ************ ***** ***** **** **** *** *** ** ** * *
Approach:
- Input number of rows to print from the user as N.
- To iterate through rows run an outer loop from number of rows till it is greater than 1. The loop structure should look like for(i=N; i>=1; i–).
- To print spaces, run an inner loop from i to space (another local variable). The loop structure should look like for(k=1; k=1; j–); .Inside this loop print star.
- After printing all columns of a row, move to next line i.e. print new line.
Below is the implementation of the above approach:
C++
// C++ program for printing // the hollow triangle pattern #include <iostream> using namespace std;
// Function for printing pattern void pattern( int N)
{ int i, j, k = 0, space = 1, rows = N;
// For printing stars
for (i = rows; i >= 1; i--) {
for (j = 1; j <= i; j++) {
cout << "*" ;
}
if (i != rows) {
// for printing space
for (k = 1; k <= space; k++) {
cout << " " ;
}
// increment by 2
space = space + 2;
}
for (j = i; j >= 1; j--) {
if (j != rows)
cout << "*" ;
}
cout << "\n" ;
}
cout << "\n" ;
} // Driver code int main()
{ // Get N
int N = 6;
// Print the pattern
pattern(N);
return 0;
} |
C
// C program for printing // the hollow triangle pattern #include <stdio.h> // Function for printing pattern void pattern( int N)
{ int i, j, k = 0, space = 1, rows = N;
// For printing stars
for (i = rows; i >= 1; i--) {
for (j = 1; j <= i; j++) {
printf ( "*" );
}
if (i != rows) {
// for printing space
for (k = 1; k <= space; k++) {
printf ( " " );
}
// increment by 2
space = space + 2;
}
for (j = i; j >= 1; j--) {
if (j != rows)
printf ( "*" );
}
printf ( "\n" );
}
printf ( "\n" );
} // Driver code int main()
{ // Get N
int N = 6;
// Print the pattern
pattern(N);
return 0;
} |
Java
// Java program for printing // the hollow triangle pattern import java.util.*;
class solution
{ // Function for printing pattern static void pattern( int N)
{ int i, j, k = 0 , space = 1 , rows = N;
// For printing stars
for (i = rows; i >= 1 ; i--) {
for (j = 1 ; j <= i; j++) {
System.out.print( "*" );
}
if (i != rows) {
// for printing space
for (k = 1 ; k <= space; k++) {
System.out.print( " " );
}
// increment by 2
space = space + 2 ;
}
for (j = i; j >= 1 ; j--) {
if (j != rows)
System.out.print( "*" );
}
System.out.print( "\n" );
}
System.out.print( "\n" );
} // Driver code public static void main(String args[])
{ // Get N
int N = 6 ;
// Print the pattern
pattern(N);
} } //This code is contributed by Surendra_Gangwar |
Python3
# Python 3 program for printing # the hollow triangle pattern # Function for printing pattern def pattern(N):
k, space, rows = 0 , 1 , N
# For printing stars
for i in range (rows, 0 , - 1 ):
for j in range ( 1 , i + 1 ):
print ( '*' , end = '')
if i ! = rows:
# for printing space
for k in range ( 1 , space + 1 ):
print ( ' ' , end = '')
# increment by 2
space + = 2
for j in range (i, 0 , - 1 ):
if j ! = rows:
print ( '*' , end = '')
print ()
print ()
# Driver Code # Get N N = 6
# Print the pattern pattern(N) # This code is contributed by # SamyuktaSHegde |
C#
// C# program for printing // the hollow triangle pattern using System;
class GFG
{ // Function for printing pattern static void pattern( int N)
{ int i, j, k = 0, space = 1, rows = N;
// For printing stars
for (i = rows; i >= 1; i--)
{
for (j = 1; j <= i; j++)
{
Console.WriteLine( "*" );
}
if (i != rows)
{
// for printing space
for (k = 1; k <= space; k++)
{
Console.Write( " " );
}
// increment by 2
space = space + 2;
}
for (j = i; j >= 1; j--)
{
if (j != rows)
Console.Write( "*" );
}
Console.Write( "\n" );
}
Console.Write( "\n" );
} // Driver code public static void Main()
{ // Get N
int N = 6;
// Print the pattern
pattern(N);
} } // This code is contributed // by Rajput-Ji |
PHP
<?php // PHP program for printing // the hollow triangle pattern // Function for printing pattern function pattern( $N )
{ $k = 0;
$space = 1;
$rows = $N ;
// For printing stars
for ( $i = $rows ; $i >= 1; $i --)
{
for ( $j = 1; $j <= $i ; $j ++)
{
echo "*" ;
}
if ( $i != $rows )
{
// for printing space
for ( $k = 1; $k <= $space ; $k ++)
{
echo " " ;
}
// increment by 2
$space = $space + 2;
}
for ( $j = $i ; $j >= 1; $j --)
{
if ( $j != $rows )
echo "*" ;
}
echo "\n" ;
}
echo "\n" ;
} // Driver code // Get N $N = 6;
// Print the pattern pattern( $N );
// This code is contributed by // Archana_kumari ?> |
Javascript
<script> // JavaScript program for printing
// the hollow triangle pattern
// Function for printing pattern
function pattern(N) {
var i,
j,
k = 0,
space = 1,
rows = N;
// For printing stars
for (i = rows; i >= 1; i--) {
for (j = 1; j <= i; j++) {
document.write( "*" );
}
if (i != rows) {
// for printing space
for (k = 1; k <= space; k++) {
document.write( " " );
}
// increment by 2
space = space + 2;
}
for (j = i; j >= 1; j--) {
if (j != rows) document.write( "*" );
}
document.write( "<br>" );
}
document.write( "<br>" );
}
// Driver code
// Get N
var N = 6;
// Print the pattern
pattern(N);
// This code is contributed by rdtank.
</script>
|
Output:
*********** ***** ***** **** **** *** *** ** ** * *
Time complexity: O(n2)
Auxiliary Space: O(1)