题解 | #Fibonacci#

#include <iostream>
using namespace std;
//f1=1,f2=1,f3=2,f4=3
int main() {
    int n;
    while(cin >> n){
        int a = 0, b = 1, c;
        if(n <= 1){
            cout << n;
        }
        else{
            for(int i = 2; i <= n; i++){
                c = a + b;
                a = b;
                b = c;
            }
            cout << c;
        }
    }
}
// 64 位输出请用 printf("%lld")