Submission #395107

#	Time	Username	Problem	Language	Result	Execution time	Memory
395107		jeroenodb	Combo (IOI18_combo)	C++14	100 / 100	55 ms	680 KiB

combo

#include "combo.h"
#include "bits/stdc++.h"
using namespace std;
#define all(x) begin(x),end(x)
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { string sep; for (const T &x : v) os << sep << x, sep = " "; return os; }
#define debug(a) cerr << "(" << #a << ": " << a << ")\n";
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pi;
const int mxN = 1e5+1, oo = 1e9;
std::string guess_sequence(int N) {
    int n = N;
    string but = "ABXY";
    if(press("AB")) {
        swap(but[press("B")], but[0]);
    } else {
        swap(but[press("Y")+2], but[0]);
    }
    string pref;
    pref+=but[0];
    if(n==1) return pref;
    for(int i=1;i<n-1;++i) {
        string query = pref+but[1];
        for(int j=1;j<4;++j) {
            query+=pref+but[2]+but[j];
        }
        int coins = press(query);
        if(coins == pref.size()) {
            pref+=but[3];
        } else if(coins == pref.size()+1) {
            pref+=but[1];
        } else {
            pref+=but[2];
        }
    }
    // check last character
    random_shuffle(but.begin()+1, but.end());
    if(press(pref+but[1]+pref+but[2])==n) {
        if(press(pref+but[1])==n) {
            pref+=but[1];
        } else pref+=but[2];
    } else pref+=but[3];
    return pref;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:30:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |         if(coins == pref.size()) {
      |            ~~~~~~^~~~~~~~~~~~~~
combo.cpp:32:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         } else if(coins == pref.size()+1) {
      |                   ~~~~~~^~~~~~~~~~~~~~~~

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