Submission #106322

#	Time	Username	Problem	Language	Result	Execution time	Memory
106322		tri	Combo (IOI18_combo)	C++14	100 / 100	72 ms	560 KiB

combo

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;

#define pb push_back
#define f first
#define s second

/*
int press(string p) {
    cout << p << endl;
    int res;
    cin >> res;
    return res;
}*/

int press(string p);

string keys[] = {"A", "B", "X", "Y"};

string guess_sequence(int N) {
    if (N == 1) {
        for (int i = 0; i < 3; i++) {
            if (press(keys[i]) == 1) {
                return keys[i];
            }
        }
        return keys[3];
    }
    string seq = "";
    int f = -1;

    int res = press("AB");
    if (res != 0) {
        res = press("A");
        if (res == 1) {
            seq.append("A");
            f = 0;
        } else {
            seq.append("B");
            f = 1;
        }
    } else {
        res = press("X");
        if (res == 1) {
            seq.append("X");
            f = 2;
        } else {
            seq.append("Y");
            f = 3;
        }
    }

    vector<string> cand(keys, keys + 4);

    cand.erase(cand.begin() + f);

    for (int i = 1; i < N - 1; i++) {
        string q = "";
        for (int j = 0; j < 3; j++) {
            q.append(seq);
            q.append(cand[0]);
            q.append(cand[j]);
        }
        q.append(seq);
        q.append(cand[1]);

        int res = press(q);

        if (res == seq.length() + 2) {
            seq.append(cand[0]);
        } else if (res == seq.length() + 1) {
            seq.append(cand[1]);
        } else {
            seq.append(cand[2]);
        }
    }

    string q = "";
    q.append(seq);
    q.append(cand[0]);
    q.append(seq);
    q.append(cand[1]);
    res = press(q);

    if (res == seq.length() + 1) {
        q = "";
        q.append(seq);
        q.append(cand[0]);
        int res = press(q);
        if (res == seq.length() + 1) {
            seq.append(cand[0]);
        } else {
            seq.append(cand[1]);
        }
    } else {
        seq.append(cand[2]);
    }
    return seq;
}

/*
int main() {
    cout << guess_sequence(5);
}*/

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:77:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |         if (res == seq.length() + 2) {
      |             ~~~~^~~~~~~~~~~~~~~~~~~
combo.cpp:79:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |         } else if (res == seq.length() + 1) {
      |                    ~~~~^~~~~~~~~~~~~~~~~~~
combo.cpp:93:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   93 |     if (res == seq.length() + 1) {
      |         ~~~~^~~~~~~~~~~~~~~~~~~
combo.cpp:98:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |         if (res == seq.length() + 1) {
      |             ~~~~^~~~~~~~~~~~~~~~~~~

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