Program to print hollow Triangle pattern
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; iā).
- 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; jā); .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)
Contact Us