Submission #277033

#	Time	Username	Problem	Language	Result	Execution time	Memory
277033		hamerin	Combo (IOI18_combo)	C++17	100 / 100	41 ms	656 KiB

combo

#include "combo.h"

#include <bits/stdc++.h>

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

using namespace std;

using i64 = long long;
using d64 = long double;
using pi = pair<int, int>;
using pli = pair<i64, i64>;
using ti = tuple<int, int, int>;
using tli = tuple<i64, i64, i64>;

#define iterall(cont) cont.begin(), cont.end()
#define prec(n) setprecision(n) << fixed

int N;

string guess_sequence(int n) {
    N = n;
    string S;

    if (press("AB")) {
        if (press("A"))
            S += 'A';
        else
            S += 'B';
    } else {
        if (press("X"))
            S += 'X';
        else
            S += 'Y';
    }

    set<char> st = {'A', 'B', 'X', 'Y'};
    st.erase(S[0]);

    vector<char> vc;
    copy(iterall(st), back_inserter(vc));

    while (S.size() < N - 1) {
        auto x = press(S + vc[0] + vc[1] + S + vc[0] + vc[2] + S + vc[0] + vc[0] + S + vc[1]) - S.size();
        if (x == 2)
            S += vc[0];
        else if (x == 1)
            S += vc[1];
        else
            S += vc[2];
    }

    if (S.size() < N) {
        if (press(S + vc[0] + S + vc[1]) - S.size()) {
            if (press(S + vc[0]) - S.size()) S += vc[0];
            else S += vc[1];
        } else {
            S += vc[2];
        }
    }

    return S;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:44:21: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   44 |     while (S.size() < N - 1) {
      |            ~~~~~~~~~^~~~~~~
combo.cpp:54:18: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   54 |     if (S.size() < N) {
      |         ~~~~~~~~~^~~

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