题解 | #统计每个月兔子的总数#

#include <iostream>
#include <vector>
using namespace std;

int main() {
 int n;
 cin >> n;
 vector<int> rabbit(2,0);

 for(int i = 1; i <=n; i++){
    int time = rabbit.size();
    for(int k = 1; k < time; k++){
        rabbit[k]+=1;
        if(rabbit[k] >=3 ) rabbit.push_back(1);
    }
 }
    cout<< rabbit.size()-1 <<endl;
    return 0;
 }