C++ program to Find Nth term of the series 1, 1, 2, 6, 24…

In this problem, we are given an integer N. Our task is to create a program to Find Nth term of series 1,1, 2, 6, 24, ...

Let’s take an example to understand the problem,

Input

N = 7

Output

720

Explanation

The series is − 1, 1, 2, 6, 24, 120, 720

Solution Approach

A simple approach to solve the problem is by using the general formula for the nth term of the series. The formula for,

Nth term = (N−1)!

Program to illustrate the working of our solution,

Example

 Live Demo

#include <iostream> using namespace std; int calcNthTerm(int N) {    if (N <= 1)       return 1;       int factorial = 1;    for (int i = 1; i < N; i++)       factorial *= i;       return factorial; } int main() {    int N = 8;    cout<<N<<"th term of the series is "<<calcNthTerm(N);    return 0; }

Output

8th term of the series is 5040