Submission #476850

#	Time	Username	Problem	Language	Result	Execution time	Memory
476850		Valaki2	Combo (IOI18_combo)	C++14	100 / 100	42 ms	580 KiB

combo

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

int n;

string ans;

vector<char> letters = {'A', 'B', 'X', 'Y'};

void getFirst() {
    char firstChar;
    int x = press("AB");
    int y = press("AX");
    if(x == 0) {
        if(y == 0) {
            firstChar = 'Y';
        } else {
            firstChar = 'X';
        }
    } else {
        if(y == 0) {
            firstChar = 'B';
        } else {
            firstChar = 'A';
        }
    }
    ans.push_back(firstChar);
    auto toErase = letters.begin();
    for(auto it = letters.begin(); it != letters.end(); it++) {
        if(*it == firstChar) {
            toErase = it;
        }
    }
    letters.erase(toErase);
}

void getLast() {
    for(int i = 0; i < 2; i++) {
        if(press(ans + letters[i]) == n) {
            ans.push_back(letters[i]);
            break;
        }
    }
    if(ans.size() != n) {
        ans.push_back(letters.back());
    }
}


string guess_sequence(int N) {
    n = N;
    getFirst();
    if(n == 1) {
        return ans;
    }
    for(int i = 2; i < n; ++i) {
        int x = press(ans + letters[0] + ans + letters[1] + letters[0] + ans + letters[1] + letters[1] + ans + letters[1] + letters[2]);
        if(x == i - 1) {
            ans.push_back(letters[2]);
        }
        if(x == i) {
            ans.push_back(letters[0]);
        }
        if(x == i + 1) {
            ans.push_back(letters[1]);
        }
    }
    getLast();
    return ans;
}

Compilation message (stderr)

combo.cpp: In function 'void getLast()':
combo.cpp:45:19: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   45 |     if(ans.size() != n) {
      |        ~~~~~~~~~~~^~~~

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