Submission #1029969

#	Time	Username	Problem	Language	Result	Execution time	Memory
1029969		thabumi	Combo (IOI18_combo)	C++17	Compilation error	0 ms	0 KiB

combo

using namespace std;
string fiAndLa(string pref) {
    string A = "A";
    string B = "B";
    string C = "X";
    string D = "Y";
    string AA = A + A, AB = A + B, AC = A + C, AD = A + D,
           BA = B + A, BB = B + B, BC = B + C, BD = B + D,
           CA = C + A, CB = C + B, CC = C + C, CD = C + D,
           DA = D + A, DB = D + B, DC = D + C, DD = D + D;
    string res = "";
    int coin = press(pref + AB);
    if (coin > pref.size()) {
        coin = press(pref + A);
        if (coin == pref.size() + 1) {
            res += A;
        }
        else {
            res += B;
        }
    }
    else {
        coin = press(pref + C);
        if (coin == pref.size() + 1) {
            res += C;
        }
        else {
            res += D;
        }
    }
    return res;
}
std::string guess_sequence(int N) {
    string A = "A";
    string B = "B";
    string C = "X";
    string D = "Y";
    string AA = A + A, AB = A + B, AC = A + C, AD = A + D,
           BA = B + A, BB = B + B, BC = B + C, BD = B + D,
           CA = C + A, CB = C + B, CC = C + C, CD = C + D,
           DA = D + A, DB = D + B, DC = D + C, DD = D + D;
    string res = "";
    int coin;
    if (N == 1) {
        res += fiAndLa(res);
    }
    else if (N == 2) {
        res += fiAndLa(res);
        res += fiAndLa(res);
    }
    else {
        res += fiAndLa(res);
        string fi = res;
        for (int i = 2; i <= N - 1; i++) {
            if (fi == A) {
                coin = press(res + BB + res + BC + res + BD + res + C);
                if (coin == res.size() + 2) {
                    res += B;
                }
                else if (coin == res.size() + 1) {
                    res += C;
                }
                else res += D;
            }
            else if (fi == B) {
                coin = press(res + AA + res + AC + res + AD + res + C);
                if (coin == res.size() + 2) {
                    res += A;
                }
                else if (coin == res.size() + 1) {
                    res += C;
                }
                else res += D;
            }
            else if (fi == C) {
                coin = press(res + BB + res + BC + res + BD + res + A);
                if (coin == res.size() + 2) {
                    res += B;
                }
                else if (coin == res.size() + 1) {
                    res += A;
                }
                else res += D;
            }
            else {
                coin = press(res + BB + res + BC + res + BD + res + C);
                if (coin == res.size() + 2) {
                    res += B;
                }
                else if (coin == res.size() + 1) {
                    res += C;
                }
                else res += A;
            }
        }
        res += fiAndLa(res);

    }
    return res;
}

Compilation message (stderr)

combo.cpp:2:1: error: 'string' does not name a type
    2 | string fiAndLa(string pref) {
      | ^~~~~~
combo.cpp:33:6: error: 'string' in namespace 'std' does not name a type
   33 | std::string guess_sequence(int N) {
      |      ^~~~~~
combo.cpp:1:1: note: 'std::string' is defined in header '<string>'; did you forget to '#include <string>'?
  +++ |+#include <string>
    1 | using namespace std;