Skip to content
Related Articles

Related Articles

Improve Article

Triangular Matchstick Number

  • Difficulty Level : Easy
  • Last Updated : 07 Aug, 2021
Geek Week

Given a number X which represents the floor of a matchstick pyramid, write a program to print the total number of matchstick required to form pyramid of matchsticks of x floors.

Examples: 

Input : X = 1
Output : 3

Input : X = 2
Output : 9 

This is mainly an extension of triangular numbers. For a number X, the matchstick required will be three times of X-th triangular numbers, i.e., (3*X*(X+1))/2


C++




// C++ program to find X-th triangular
// matchstick number
 
#include <bits/stdc++.h>
using namespace std;
 
int numberOfSticks(int x)
{
    return (3 * x * (x + 1)) / 2;
}
 
int main()
{
    cout<<numberOfSticks(7);
    return 0;
}

Java




// Java program to find X-th triangular
// matchstick number
public class TriangularPyramidNumber {
    public static int numberOfSticks(int x)
    {
        return (3 * x * (x + 1)) / 2;
    }
    public static void main(String[] args)
    {
        System.out.println(numberOfSticks(7));
    }
}

Python3




# Python program to find X-th triangular
# matchstick number
 
def numberOfSticks(x):
    return (3 * x * (x + 1)) / 2
     
# main()
print(int(numberOfSticks(7)))

C#




// C# program to find X-th triangular
// matchstick number
using System;
 
class GFG
{
    // Function to ind missing number
    static int numberOfSticks(int x)
    {
        return (3 * x * (x + 1)) / 2;
    }
 
    public static void Main()
    {
        Console.Write(numberOfSticks(7));
    }
}
 
// This code is contributed by _omg

PHP




<?php
// PHP program to find
// X-th triangular
// matchstick number
 
function numberOfSticks($x)
{
    return (3 * $x * ($x + 1)) / 2;
}
 
// Driver code
echo(numberOfSticks(7));
 
// This code is contributed by Ajit.
?>

Javascript




<script>
// javascript program to find X-th triangular
// matchstick number
 
function numberOfSticks( x)
{
    return (3 * x * (x + 1)) / 2;
}
 
   document.write(numberOfSticks(7));
 
// This code is contributed by aashish1995
 
</script>
Output: 
84

 

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.  To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

In case you wish to attend live classes with experts, please refer DSA Live Classes for Working Professionals and Competitive Programming Live for Students.




My Personal Notes arrow_drop_up
Recommended Articles
Page :