ft1.cpp

// 再帰の基本：階乗

#include <iostream>

using namespace std;

int factrial(int n)
{
    if (n <1){
        return 1;
    }else{
        return  n*factrial(n-1);
    }
}

int main()
{
    int n;
    cout << "nを入力:";
    cin >> n;
    cout << "n = " << n << "  n! = " << factrial(n) <<endl;
    return 0;
}