Given a number n, find the n-th icosahedral number. The Icosahedral Number is class of figurative number that represents an icosahedron(a polyhedron with 20 faces.
The first few Icosahedral Numbers are 1, 12, 48, 124, 255, 456, 742, 1128, 1629…………..
Examples:
Input : 5
Output :255
Input :10
Output :2260
n-th term of Icosahedral Number is given by:
Basic implementation of the above idea:
C++
#include <bits/stdc++.h>
using namespace std;
int icosahedralnum( int n)
{
return (n * (5 * n * n - 5 * n + 2)) / 2;
}
int main()
{
int n = 7;
cout << icosahedralnum(n);
return 0;
}
|
C
#include <stdio.h>
int icosahedralnum( int n)
{
return (n * (5 * n * n - 5 * n + 2)) / 2;
}
int main()
{
int n = 7;
printf ( "%d" ,icosahedralnum(n));
return 0;
}
|
Java
import java.io.*;
class GFG {
static int icosahedralnum( int n)
{
return (n * ( 5 * n * n - 5 *
n + 2 )) / 2 ;
}
public static void main (String[] args)
{
int n = 7 ;
System.out.println(
icosahedralnum(n));
}
}
|
Python3
def icosahedralnum(n) :
return (n * ( 5 * n * n -
5 * n + 2 )) / / 2
if __name__ = = '__main__' :
n = 7
print (icosahedralnum(n))
|
C#
using System;
class GFG
{
static int icosahedralnum( int n)
{
return (n * (5 * n * n -
5 * n + 2)) / 2;
}
static public void Main ()
{
int n = 7;
Console.WriteLine(icosahedralnum(n));
}
}
|
PHP
<?php
function icosahedralnum( $n )
{
return ( $n * (5 * $n * $n -
5 * $n + 2)) / 2;
}
$n = 7;
echo icosahedralnum( $n );
?>
|
Javascript
<script>
function icosahedralnum(n)
{
return (n * (5 * n * n - 5 * n + 2)) / 2;
}
let n = 7;
document.write(icosahedralnum(n));
</script>
|
Output:
742
Time Complexity: O(1)
Auxiliary Space: O(1)
Last Updated :
19 May, 2022
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