Submission #1278937

#	Time	Username	Problem	Language	Result	Execution time	Memory
1278937		North1304	Combo (IOI18_combo)	C++20	100 / 100	9 ms	596 KiB

combo

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

string guess_sequence(int n) {
    string ans;
    if (press("AB")) {
        if (press("A")) ans = "A";
        else ans = "B";
    }
    else {
        if (press("X")) ans = "X";
        else ans = "Y";
    }
    if (n==1) return ans;
    vector<string> test;
    if (ans!="A") test.push_back("A");
    if (ans!="B") test.push_back("B");
    if (ans!="X") test.push_back("X");
    if (ans!="Y") test.push_back("Y");
    for (int i=2;i<n;i++) {
        string s1 = ans + test[0];
        string s2 = ans + test[1] + test[0];
        string s3 = ans + test[1] + test[1];
        string s4 = ans + test[1] + test[2];
        int now = press(s1 + s2 + s3 + s4);
        if (now==i) ans += test[0];
        else if (now==i+1) ans += test[1];
        else if (now==i-1) ans += test[2];
    } 
    if (press(ans + "A" + ans + "B")==n) {
        if (press(ans + "A")==n) return ans + "A";
        else return ans + "B";
    }
    else {
        if (press(ans + "X")==n) return ans + "X";
        else return ans + "Y";
    }
}

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