factorial using recursion with memrisation in c++ code example

Example: c++ factorial

#include <cmath>

int fact(int n){
    return std::tgamma(n + 1);  
}    
// for n = 5 -> 5 * 4 * 3 * 2 = 120 
//tgamma performas factorial with n - 1 -> hence we use n + 1