[Recursion] Factorial

 

Factorial – a simple recursion

 

n! (Recursive function)

if n>0

→ n x (n-1)!

if n=0

→ 1

 

예제)

#include<iostream>

#include<cstdio>

int Factorial(int n) {

            cout<<”I am calculating F(“<<n<<”)\n”;

            if(n==0) {

                        return 1;

            }

            int F = n * Factorial(n-1);

            cout<<”Done !F(“<<n<<”) = “<<F<<”\n”;

            return F;

}

 

int main() {

            int n;

            cout<<”Give me an n: ”;

            cin>>n;

           

            int result = Factorial(n);

            cout<<result;

}

 

실행 결과)

Give me an n: 5

I am calculating F(5)

I am calculating F(4)

I am calculating F(3)

I am calculating F(2)

I am calculating F(1)

I am calculating F(0)

Done !F(1) = 1

Done !F(2) = 2

Done !F(3) = 6

Done !F(4) = 24

Done !F(5) = 120

120

 

 

 

 

 

↓ 참고 사이트

https://www.youtube.com/watch?v=_OmRGjbyzno&list=PL2_aWCzGMAwLz3g66WrxFGSXvSsvyfzCO&index=1