Submission #1037952

#	Time	Username	Problem	Language	Result	Execution time	Memory
1037952		RecursiveCo	Combo (IOI18_combo)	C++17	100 / 100	22 ms	2232 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"

using namespace std;

#define in(i) cin >> i
#define out(o) cout << o

string guess_sequence(int N) {
    string ans = "";
    int first = press("AB");
    vector<string> left;
    if (first) {
        first = press("A");
        if (first) ans += "A", left.push_back("B"), left.push_back("X"), left.push_back("Y");
        else ans += "B", left.push_back("A"), left.push_back("X"), left.push_back("Y");
    } else {
        first = press("X");
        if (first) ans += "X", left.push_back("B"), left.push_back("A"), left.push_back("Y");
        else ans += "Y", left.push_back("B"), left.push_back("X"), left.push_back("A");
    }
    for (int i = 0; i < N - 2; i++) {
        string inp = (ans + left[0]) + (ans + left[1] + left[0]) + (ans + left[1] + left[1]) + (ans + left[1] + left[2]);
        int res = press(inp);
        if (res == i + 1) {
            ans += left[2];
        } else if (res == i + 2) {
            ans += left[0];
        } else {
            ans += left[1];
        }
    }
    if (N != 1) {
        int last = press(ans + left[0]);
        if (last == N) ans += left[0];
        else {
            last = press(ans + left[1]);
            if (last == N) ans += left[1];
            else ans += left[2];
        }
    }
    return ans;
}

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