Submission #939399

#	Time	Username	Problem	Language	Result	Execution time	Memory
939399		ifateen	Combo (IOI18_combo)	C++14	100 / 100	15 ms	1772 KiB

combo

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

string guess_sequence(int N) {
    string ans;
    vector<string> possible = {"A", "B", "X", "Y"};
    // A
    if (press("AB")) {
        if (press("A")) ans += 'A', possible = {"B", "X", "Y", "A"};
        else ans += 'B', possible = {"A", "X", "Y", "B"};
    } else {
        if (press("X")) ans += 'X', possible = {"A", "B", "Y", "X"};
        else ans += 'Y';
    }
    while (ans.size() < N - 1) {
        string query = ans + possible[1] + ans + possible[2] + possible[0] + ans + possible[2] + possible[1] + ans + possible[2] + possible[2];
        int ret = press(query);
        if (ret == ans.size()) {
            ans += possible[0];
        } else if (ret == ans.size() + 1) {
            ans += possible[1];
        } else {
            ans += possible[2];
        }
    }
    if (ans.size() == N) return ans;
    int zero = press(ans + possible[0]);
    if (zero == N) return (ans += possible[0]);
    int one = press(ans + possible[1]);
    if (one == N) return (ans += possible[1]);
    return (ans += possible[2]);
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:16:23: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   16 |     while (ans.size() < N - 1) {
      |            ~~~~~~~~~~~^~~~~~~
combo.cpp:19:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |         if (ret == ans.size()) {
      |             ~~~~^~~~~~~~~~~~~
combo.cpp:21:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |         } else if (ret == ans.size() + 1) {
      |                    ~~~~^~~~~~~~~~~~~~~~~
combo.cpp:27:20: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   27 |     if (ans.size() == N) return ans;
      |         ~~~~~~~~~~~^~~~

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