C++ 解法, 执行用时: 2ms, 内存消耗: 484KB, 提交时间: 2020-12-29

#include <bits/stdc++.h>
using namespace std;
class FoldPaper {
public:
    void fold(vector<string>&v,int n,string s){
        if(n>0){
            fold(v,n-1,"down");
            v.push_back(s);
            fold(v,n-1,"up");
        }
    }
vector<string> foldPaper(int n) {
    // write code here
    vector<string>ans;
    fold(ans, n, "down");
    return ans;
}
};

C++ 解法, 执行用时: 2ms, 内存消耗: 484KB, 提交时间: 2020-11-22

class FoldPaper {
public:
    vector<string> foldPaper(int n) {
        vector<string> ret;
        foldPaper(n, 1, true, ret);// write code here
        return ret;
    }
private:
    void foldPaper(int N, int i, bool down, vector<string> & ret) {
        if (i > N) return;
        foldPaper(N, i + 1, true, ret);
        down == true ? ret.push_back("down") : ret.push_back("up");
        foldPaper(N, i + 1, false, ret);
    }
};