Given a number N. The task is to write a program to find the Nth term in the below series:
1, 1, 2, 6, 24…
Examples:
Input: 3 Output: 2 For N = 3 Nth term = (N-1)! = 2 Input: 5 Output: 24
Nth term of the series is given by below formula:
Nth term = ( N-1)!
Below is the required implementation:
C++
// CPP program to find N-th term of the series: // 1, 1, 2, 6, 24... #include <iostream> using namespace std; // calculate Nth term of series int nthTerm( int N) { if (N <= 1) return 1; int i, fact = 1; for (i = 1; i < N; i++) fact = fact * i; return fact; } // Driver Function int main() { int N = 3; cout << nthTerm(N); return 0; } |
Java
// Java program to find the Nth term import java.io.*; // calculate Nth term of this series // 1, 1, 2, 6, 24... class Nth { public int nthTerm( int N) { // By using above formula if (N <= 1 ) return 1 ; int i, fact = 1 ; for (i = 1 ; i < N; i++) fact = fact * i; return fact; } } // Main class for main method class GFG { public static void main(String[] args) { int N = 3 ; // create object of Class Nth Nth a = new Nth(); // call and print Nth term System.out.println(a.nthTerm(N)); } } |
Python 3
# Python 3 program to find # N-th term of the series: # 1, 1, 2, 6, 24... # Function to calculate # Nth term of series def nthTerm(n) : if n < = 1 : return 1 fact = 1 for i in range ( 1 , N) : fact = fact * i return fact # Driver code if __name__ = = "__main__" : N = 3 # function calling print (nthTerm(N)) # This code is contributed # by ANKITRAI1 |
C#
// C# program to find the // Nth term of the series // 1, 1, 2, 6, 24... using System; // calculate Nth term class GFG { public int nthTerm( int N) { // By using above formula if (N <= 1) return 1; int i, fact = 1; for (i = 1; i < N; i++) fact = fact * i; return fact; } // Driver Code public static void Main() { int N = 3; // create object of Class GFG GFG a = new GFG(); // call and print Nth term Console.Write(a.nthTerm(N)); } } // This code is contributed // by ChitraNayal |
PHP
<?php // PHP program to find N-th // term of the series: // 1, 1, 2, 6, 24... // calculate Nth term of series function nthTerm( $N ) { if ( $N <= 1) return 1; $fact = 1; for ( $i = 1; $i < $N ; $i ++) $fact = $fact * $i ; return $fact ; } // Driver Code $N = 3; echo nthTerm( $N ); // This code is contributed // by ChitraNayal ?> |
Javascript
<script> // JavaScript program to find N-th term of the series: // 1, 1, 2, 6, 24... // calculate Nth term of series function nthTerm( N) { if (N <= 1) return 1; let i, fact = 1; for (i = 1; i < N; i++) fact = fact * i; return fact; } // Driver Function let N = 3; document.write(nthTerm(N)); // This code contributed by Rajput-Ji </script> |
2
Time Complexity: O(N), where N represents the given integer.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
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