题解 | #统计每个月兔子的总数#

#include <iostream>
using namespace std;

int main() {
    int fir=1;
    int sec=0;
    int n=0;
    cin>>n;
    int tem = 0;
    //cout<<1<<" fir:"<<fir<<" sec:"<<sec<<endl;
    for(int i = 2;i<=n;i++){
        tem = sec;
        sec += fir;
        fir = 0;
        fir = tem;
        //cout<<i<<" fir:"<<fir<<" sec:"<<sec<<endl;
    }
    cout<<fir+sec;
}
// 64 位输出请用 printf("%lld")