Submission #1023377

#	Time	Username	Problem	Language	Result	Execution time	Memory
1023377		vanea	Combo (IOI18_combo)	C++14	0 / 100	0 ms	596 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
using ll = long long;

string guess_sequence(int n) {
    vector<string> pos = {"A", "B", "X", "Y"};
    string ans = "";
    if(press("AB")) {
        if(press("A")) ans += "A";
        else ans += "B";
    }
    else {
        if(press("X")) ans += "X";
        else ans += "Y";
    }
    int last = 1;
    string res = string(1, ans[0]);
    for(int i = 1; i < n; i++) {
        if(i == n-1) {
            string curr = "", last1 = "";
            for(auto it : pos) {
                if(it == res) continue;
                if(curr.length() == ans.length()+2) {
                    last1 = ans+it;
                }
                else {
                    curr += ans;
                    curr += it;
                }
            }
            if(press(curr) == last+1) {
                string curr1 = ans + curr[ans.length()];
                string curr2 = ans + curr[curr.length()-1];
                if(press(curr1) == last+1) ans += curr[ans.length()];
                else ans += curr[curr.length()-1];
            }
            else {
                ans += last1[last1.length()-1];
            }
        }
        else {
            string f = "", s = "", t = "";
            for(auto it : pos) {
                if(it == res) continue;
                if(f == "") f = it;
                else if(s == "") s = it;
                else t = it;
            }
            string curr = ans + f + s + ans + f + f + ans + f + t + ans + s;
            int k = press(curr);
            if(k == last+2) {
                ans += f;
            }
            else if(k == last+1) {
                ans += s;
            }
            else ans += t;
        }
        ++last;
    }
    if((int)ans.length() != n) {
        while(1) {}
    }
    return ans;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 95