# Maximum value of an integer for which factorial can be calculated on a machine

• Difficulty Level : Medium
• Last Updated : 03 Jun, 2022

Program to find maximum value of an integer for which factorial can be calculated on a machine, assuming that factorial is stored using basic data type like long long int.

The idea is based on that fact that, in most of the machines, when we cross limit of integer, the values becomes negative.

## C++

 `// C++ program to find maximum value of``// an integer for which factorial can``// be calculated on your system``#include ``using` `namespace` `std;` `int` `findMaxValue()``{``    ``int` `res = 2;``    ``long` `long` `int` `fact = 2;``    ``while` `(1)``    ``{``        ``// when fact crosses its size,``        ``// it gives negative value``        ``if` `(fact < 0)``            ``break``;``        ``res++;``        ` `        ``// You cannot use fact = fact*res,``        ``// for overflow negative condition in C++``        ``// If you use this then it will give``        ``// an error,``        ``// "signed integer overflow: 2432902008176640000 * 21``        ``// cannot be represented in type 'long long' "``        ``// To avoid this, use the below code.``        ``// This error won't occur in languages like java, python,``        ``// JavaScript. as they have garbage collectors for such errors.``        ``if``(fact > LLONG_MAX/res){``            ``break``;``        ``}``        ``else``{``            ``fact = fact*res;``        ``}``    ``}``    ``return` `res - 1;``}` `// Driver Code``int` `main()``{``    ``cout << ``"Maximum value of integer : "``;``    ``cout <<  findMaxValue() << endl;``    ``return` `0;``}` `// The code is contributed by Gautam goel (gautamgoel962)`

## C

 `// C program to find maximum value of``// an integer for which factorial can``// be calculated on your system``#include ` `int` `findMaxValue()``{``    ``int` `res = 2;``    ``long` `long` `int` `fact = 2;``    ``while` `(1)``    ``{``        ``// when fact crosses its size,``        ``// it gives negative value``        ``if` `(fact < 0)``            ``break``;``        ``res++;``        ``// You cannot use fact = fact*res,``        ``// for overflow negative condition in C``        ``// If you use this then it will give``        ``// an error,``        ``// "signed integer overflow: 2432902008176640000 * 21``        ``// cannot be represented in type 'long long' "``        ``// To avoid this, use the below code.``        ``// This error won't occur in languages like java, python,``        ``// JavaScript. as they have garbage collectors for such errors.``        ``if``(fact > LLONG_MAX/res){``            ``break``;``        ``}``        ``else``{``            ``fact = fact*res;``        ``}``    ``}``    ``return` `res - 1;``}` `// Driver Code``int` `main()``{``    ``printf` `(``"Maximum value of integer : %d\n"``, findMaxValue());``    ``return` `0;``}` `// The code is contributed by Gautam goel (gautamgoel962)`

## Java

 `// Java program to find maximum value of``// an integer for which factorial can be``// calculated on your system``import` `java.io.*;``import` `java.util.*;` `class` `GFG``{``    ``public` `static` `int` `findMaxValue()``    ``{``        ``int` `res = ``2``;``        ``long` `fact = ``2``;``        ``while` `(``true``)``        ``{``            ``// when fact crosses its size,``            ``// it gives negative value``            ``if` `(fact < ``0``)``                ``break``;``            ``res++;``            ``fact = fact * res;``        ``}``        ``return` `res - ``1``;``    ``}` `    ``// Driver Code``    ``public` `static` `void` `main(String[] args)``    ``{``        ``System.out.println(``"Maximum value of"``+``                                 ``" integer "` `+``                              ``findMaxValue());``    ``}``}`

## Python3

 `# Python3 program to find maximum value of``# an integer for which factorial can be``# calculated on your system``import` `sys``def` `findMaxValue():` `    ``res ``=` `2``;``    ``fact ``=` `2``;``    ``while` `(``True``):``        ` `        ``# when fact crosses its size``        ``# it gives negative value``        ``if` `(fact < ``0` `or` `fact > sys.maxsize):``            ``break``;``        ``res ``+``=` `1``;``        ``fact ``=` `fact ``*` `res;``    ``return` `res ``-` `1``;` `# Driver Code``if` `__name__ ``=``=` `'__main__'``:``    ` `    ``print``(``"Maximum value of integer:"``,``                      ``findMaxValue());``    ` `# This code is contributed by 29AjayKumar`

## C#

 `// C# program to find maximum value of``// an integer for which factorial can``// be calculated on your system``using` `System;` `class` `GFG``{``    ``public` `static` `int` `findMaxValue()``    ``{``        ``int` `res = 2;``        ``long` `fact = 2;``        ``while` `(``true``)``        ``{``            ``// when fact crosses its size,``            ``// it gives negative value``            ``if` `(fact < 0)``                ``break``;``            ``res++;``            ``fact = fact * res;``        ``}``        ``return` `res - 1;``    ``}` `    ``// Driver Code``    ``public` `static` `void` `Main()``    ``{``        ``Console.Write(``"Maximum value of"``+``                            ``" integer "` `+``                         ``findMaxValue());``    ``}``}` `// This code is contributed by nitin mittal`

## PHP

 ` 0)``            ``break``;``        ``\$res``++;``        ``\$fact` `= ``\$fact` `* ``\$res``;``    ``}``    ``return` `\$res` `- 1;``}` `// Driver Code``echo` `"Maximum value of"``.``           ``" integer "` `.``         ``findMaxValue();``    ` `// This code is contributed by Sam007``?>`

## Javascript

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Output :

`Maximum value of integer : 20`

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