Submission #576250

#	Time	Username	Problem	Language	Result	Execution time	Memory
576250		teki	Combo (IOI18_combo)	C++11	100 / 100	37 ms	636 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"

typedef long long ll;

#define pb push_back
#define MS(x,y) memset((x),(y),sizeof((x)))
const ll MN = 1000000007;

using namespace std;

char seq[] = {'A','B','X','Y'};

//int press(string p) {
//    cout<<"? "<<p<<endl;
//    int br;
//    cin>>br;
//    return br;
//}

string guess_sequence(int n) {
    string curr;

    int ans1 = press("AB");
    if (ans1 > 0) {
        int ans2 = press("A");
        if (ans2 > 0) curr = "A";
        else curr = "B";
    } else {
        int ans2 = press("X");
        if (ans2 > 0) curr = "X";
        else curr = "Y";
    }

    if (n == 1) return curr;

    for (int i = 1; i<n-1; i++) {
        string query;
        int ctr = 1;

        char koi[3];

        for (int j = 0; j<4; j++) {
            if (curr[0] == seq[j]) continue;

            koi[ctr-1] = seq[j];

            if (ctr == 1) query += curr+seq[j];
            else if (ctr == 2) {
                string tmp = curr+seq[j];
                for (int k = 0; k<4; k++) {
                    if (curr[0] == seq[k]) continue;

                    query += tmp+seq[k];
                }
            }
            ctr++;
        }

        int ans = press(query);

        if (ans == curr.length()) curr += koi[2];
        else if (ans == curr.length()+1) curr += koi[0];
        else if (ans == curr.length()+2) curr += koi[1];
    }

    char koi[3];
    int ctr = 0;

    for (int i = 0; i<4; i++) {
        if (seq[i] == curr[0]) continue;
        koi[ctr] = seq[i];
        if (ctr >= 2) break;

        string query = curr;
        query += seq[i];

        if (press(query) >= n) {
            curr += seq[i];
            break;
        }

        ctr++;
    }

    if (curr.length() < n) curr += koi[2];

    return curr;
}

//int main()
//{
//    #if LOCAL_DEBUG
//        fstream cin("in.txt");
//    #endif
//
//    ios_base::sync_with_stdio(false);
//    cin.tie(0);
//    cout.tie(0);
//
//    string secret = "A";
//    cout<<guess_sequence(secret.length());
//
//    return 0;
//}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:62:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |         if (ans == curr.length()) curr += koi[2];
      |             ~~~~^~~~~~~~~~~~~~~~
combo.cpp:63:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |         else if (ans == curr.length()+1) curr += koi[0];
      |                  ~~~~^~~~~~~~~~~~~~~~~~
combo.cpp:64:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |         else if (ans == curr.length()+2) curr += koi[1];
      |                  ~~~~^~~~~~~~~~~~~~~~~~
combo.cpp:86:23: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   86 |     if (curr.length() < n) curr += koi[2];
      |         ~~~~~~~~~~~~~~^~~

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