Program to find the sum of a Series 1/1! + 2/2! + 3/3! + 4/4! +…….+ n/n!

You have been given a series 1/1! + 2/2! + 3/3! + 4/4! +…….+ n/n!, find out the sum of the series till nth term.
Examples :

Input :n = 5
Output : 2.70833

Input :n = 7
Output : 2.71806

A simple solution is to one by one computer terms. For every term, find its corresponding factorial value.
An efficient solution is to do factorial computations in same loop.

Output:

Sum: 2.70833

Time Complexity: O(n)

Auxiliary Space: O(1), since no extra space has been taken.