Submission #657243

#	Time	Username	Problem	Language	Result	Execution time	Memory
657243		device	Combo (IOI18_combo)	C++17	100 / 100	31 ms	532 KiB

combo

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
string s = "ABXY", str;
int press(string p);
string guess_sequence(int n) {
     str += s[(press("AB") ? 0 : 2) + (press("AX") ? 0 : 1)];
    char c[3];
    int ptr = 0;
    for (char C:s) {
        if (C != str[0]) {
            c[ptr] = C, ptr++;
        }
    }
    if (n == 1) return str;
    for (int i = 2; i < n; i++) {
        string cur = str + c[2] + c[0] + str + c[2] + c[1] + str + c[2] + c[2] + str + c[1];
        int val = press(cur);
        val -= i - 1;
        str += c[val];
    }
    if (press(str + c[0]) == n) str += c[0];
    else if (press(str + c[1]) == n) str += c[1];
    else str += c[2];
    return str;
}

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