Maximum value of an integer for which factorial can be calculated on a machine in C++

In this problem, we need to create a program to find Maximum value of an integer for which factorial can be calculated on a machine in C++.

Factorial of a number is a huge value, as it is the product of all values preceding it. And C++ can handle large values only upto a certain value by using its inbuilt function. We need to find this restriction.

Solution Approach

We will simply use the property of data types which is when the numbers exceed the maximum value a negative number is returned.

We will use long long int which is the largest basic data type.

Example

 Live Demo

#include <iostream>
using namespace std;
int calcMaxFactVal(){
   int maxVal = 1;
   long long int maxFactorial = 1;
   while (true){
      if (maxFactorial < 0)
         return (maxVal - 1);
      maxVal++;
      maxFactorial *= maxVal;
   }
   return - 1;
}
int main(){
   cout<<"The maximum value of an integer for which factorial can be
   calculated on machine is "<<calcMaxFactVal();
   return 0;
}

Output

The maximum value of an integer for which factorial can be calculated on
machine is 20