# 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
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

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.

## CPP

 `// CPP program to print  ` `// the sum of series ` `#include ` `using` `namespace` `std; ` ` `  `// function to calculate ` `// sum of given series ` `double` `sumOfSeries(``double` `num) ` `{ ` `    ``double` `res = 0, fact = 1; ` `    ``for` `(``int` `i = 1; i <= num; i++) ` `    ``{ ` `        ``// fact variable store  ` `        ``// factorial of the i ` `        ``fact = fact * i; ` ` `  `        ``res = res + (i / fact); ` `    ``} ` `    ``return``(res); ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``double` `n = 5; ` `    ``cout << ``"Sum: "` `<< sumOfSeries(n); ` `    ``return` `0; ` `} `

## Java

 `// Java program to print ` `// the sum of series ` ` `  `import` `java.io.*; ` `import` `java.lang.*; ` ` `  `class` `GFG ` `{ ` `    ``public` `static` `double` `sumOfSeries(``double` `num) ` `    ``{ ` `        ``double` `res = ``0``, fact = ``1``; ` `        ``for` `(``int` `i = ``1``; i <= num; i++) ` `        ``{ ` `            ``// fact variable store ` `            ``// factorial of the i ` `            ``fact = fact * i; ` ` `  `            ``res = res + (i / fact); ` `        ``} ` `        ``return``(res); ` `    ``} ` ` `  `    ``// Driver Code ` `    ``public` `static` `void` `main (String[] args) ` `    ``{ ` `        ``double` `n = ``5``; ` `        ``System.out.println(``"Sum: "` `+ sumOfSeries(n)); ` `    ``} ` `} ` ` `  `// This code is contributed by  ` `// Mohit Gupta_OMG <(0_o)> `

## Python3

 `# Python code to find smallest K-digit   ` `# number divisible by X ` ` `  `def` `sumOfSeries(num): ` `     `  `    ``# Computing MAX ` `    ``res ``=` `0` `    ``fact ``=` `1` `     `  `    ``for` `i ``in` `range``(``1``, num``+``1``): ` `        ``fact ``*``=` `i ` `        ``res ``=` `res ``+` `(i``/` `fact) ` `         `  `    ``return` `res ` `     `  ` `  `n ``=` `5` `print``(``"Sum: "``, sumOfSeries(n)) ` ` `  `# Code contributed by  ` `# Mohit Gupta_OMG <(0_o)> `

## C#

 `// C# program to print the sum of series ` `using` `System; ` ` `  `class` `GFG ` `{ ` `    ``public` `static` `float` `sumOfSeries(``double` `num) ` `    ``{ ` `        ``float` `res = 0, fact = 1; ` `        ``for` `(``int` `i = 1; i <= num; i++) ` `        ``{ ` `            ``// fact variable store  ` `            ``// factorial of the i ` `            ``fact = fact * i; ` ` `  `            ``res = res + (i / fact); ` `        ``} ` `        ``return``(res); ` `    ``} ` ` `  `    ``// Driver Code ` `    ``public` `static` `void` `Main () ` `    ``{ ` `        ``double` `n = 5; ` `        ``Console.Write(``"Sum: "` `+ sumOfSeries(n)); ` `    ``} ` `} ` ` `  `// This code is contributed by vt_m. `

## PHP

 ` `

Output:

```Sum: 2.70833
```

Time Complexity: O(n)

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