Submission #477455

#	Time	Username	Problem	Language	Result	Execution time	Memory
477455		SlavicG	Combo (IOI18_combo)	C++17	100 / 100	34 ms	660 KiB

combo

#include "combo.h"
#include "bits/stdc++.h"
using namespace std;
 
#define ll long long
 
#define       forn(i,n)              for(int i=0;i<n;i++)
#define          all(v)              v.begin(), v.end()
#define         rall(v)              v.rbegin(),v.rend()
 
#define            pb                push_back
#define          sz(a)               (int)a.size()

string guess_sequence(int n){
    string cur = "";
    vector<char> c;
    c.pb('X');
    c.pb('Y');
    c.pb('A');
    c.pb('B');
    char first = 'f';
    if(press("XY")){
        if(press("X"))first = 'X';
        else first = 'Y';
    }else{
        if(press("A"))first = 'A';
        else first = 'B';
    }
    c.erase(find(all(c), first));
    assert(sz(c) == 3);
    cur += first;

    for(int i = 1;i < n - 1;++i){
        string qr = cur;
        qr += c[0];
        qr += c[0];

        qr += cur;
        qr += c[0];
        qr += c[1];

        qr += cur;
        qr += c[0];
        qr += c[2];

        qr += cur;
        qr += c[1];

        int x = press(qr);
        if(x == 2 + cur.size()){
            cur += c[0];
        }else if(x == 1 + cur.size()){
            cur += c[1];
        }else{
            cur += c[2];
        }
    }

    if(sz(cur) < n){
        if(press(cur + c[0]) == n)cur += c[0];
        else if(press(cur + c[1]) == n)cur += c[1];
        else cur += c[2]; 
    }
    assert(sz(cur) == n);
    return cur;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:50:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |         if(x == 2 + cur.size()){
      |            ~~^~~~~~~~~~~~~~~~~
combo.cpp:52:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |         }else if(x == 1 + cur.size()){
      |                  ~~^~~~~~~~~~~~~~~~~

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