Submission #95650

#	Time	Username	Problem	Language	Result	Execution time	Memory
95650		lyc	Combo (IOI18_combo)	C++14	100 / 100	47 ms	600 KiB

combo

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

std::string guess_sequence(int N) {
    string p = "AB";
    string s = "";
    int coins = press(p);
    if (coins == 0) {
        p = "X";
        coins = press(p);
        if (coins == 0) s = "Y";
        else s = "X";
    }
    else {
        p = "A";
        coins = press(p);
        if (coins == 0) s = "B";
        else s = "A";
    }

    string ok = "";
    if (s != "A") ok += 'A';
    if (s != "B") ok += 'B';
    if (s != "X") ok += 'X';
    if (s != "Y") ok += 'Y';

    for (int i = 1; i < N-1; ++i) {
        p = s+ok[0]+ok[0] + s+ok[0]+ok[1] + s+ok[0]+ok[2] + s+ok[1];
        int coins = press(p);
        if (coins == s.length()) s += ok[2];
        else if (coins == s.length()+1) s += ok[1];
        else s += ok[0];
    }
    if (N > 1) {
        p = s+ok[0] + s+ok[1];
        coins = press(p);
        if (coins == s.length()) s += ok[2];
        else {
            p = s+ok[0];
            int coins = press(p);
            if (coins == s.length()) s += ok[1];
            else s += ok[0];
        }
    }

    return s;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:31:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |         if (coins == s.length()) s += ok[2];
      |             ~~~~~~^~~~~~~~~~~~~
combo.cpp:32:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         else if (coins == s.length()+1) s += ok[1];
      |                  ~~~~~~^~~~~~~~~~~~~~~
combo.cpp:38:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |         if (coins == s.length()) s += ok[2];
      |             ~~~~~~^~~~~~~~~~~~~
combo.cpp:42:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |             if (coins == s.length()) s += ok[1];
      |                 ~~~~~~^~~~~~~~~~~~~

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