Submission #750214

#	Time	Username	Problem	Language	Result	Execution time	Memory
750214		cheat_when_I_was_young	Combo (IOI18_combo)	C++17	Compilation error	0 ms	0 KiB

combo

#include<bits/stdc++.h>
#include "combo.h"
using namespace std;
string guess_sequence(int n) {
    int coins;
    string ans = "";
    coins = press(ans + "AB");
    if (coins) {
        coins = press(ans + "A");
        if (coins) ans += "A";
        else ans += "B";
    } else {
        coins = press(ans + "X");
        if (coins) ans += "X";
        else ans += "Y";
    }
    vector<string> d, e;
    vector<char> c = {'A', 'B', 'X', 'Y'};
    if (ans == "A") {
        d = {"B", "XB", "XX", "XY"};
        e = {"Y", "B", "X"};
    } else if (ans == "B") {
        d = {"A", "XA", "XX", "XY"};
        e = {"Y", "A", "X"};
    } else if (ans[0] == "X") {
        d = {"A", "YA", "YB", "YY"};
        e = {"B", "A", "Y"};
    } else {
        d = {"A", "XA", "XB", "XX"};
        e = {"B", "A", "X"};
    }
    while (ans.size() < n-1) {
        coins = press(ans + d[0] + ans + d[1] + ans + d[2] + ans + d[3]);
        ans += e[coins - ans.size()];
    }
    coins = press(ans + "AB");
    if (coins) {
        coins = press(ans + "A");
        if (coins) ans += "A";
        else ans += "B";
    } else {
        coins = press(ans + "X");
        if (coins) ans += "X";
        else ans += "Y";
    }
    return ans;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:25:23: warning: comparison with string literal results in unspecified behavior [-Waddress]
   25 |     } else if (ans[0] == "X") {
combo.cpp:25:23: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
combo.cpp:32:23: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   32 |     while (ans.size() < n-1) {
      |            ~~~~~~~~~~~^~~~~