Submission #1007102

#	Time	Username	Problem	Language	Result	Execution time	Memory
1007102		devariaota	Combo (IOI18_combo)	C++17	100 / 100	27 ms	2020 KiB

combo

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> 
#include <ext/pb_ds/tree_policy.hpp> 
#include "combo.h"
using namespace __gnu_pbds; 
using namespace std;
#define ll long long
#define fi first
#define se second
#define endl '\n'

template <typename T>
using ordered_set = tree<T, null_type,less<T>, rb_tree_tag,tree_order_statistics_node_update>; 

const ll MOD = 1e9 + 7;
const ll INF = 1e18;

int n;

string guess_sequence(int n){
    string p = "AB", s = "";
    if(press(p)){
        p = "A";
        if(press(p)) s += p;
        else s += "B";
    } else {
        p = "X";
        if(press(p)) s += p;
        else s += "Y";
    }
    
    if(n == 1) return s;
    
    vector<char> ch;
    if(s[0] != 'A') ch.push_back('A');
    if(s[0] != 'B') ch.push_back('B');
    if(s[0] != 'X') ch.push_back('X');
    if(s[0] != 'Y') ch.push_back('Y');
    
    while(s.length() + 2 <= n){
        p = "";    
        for(int i = 0; i < 3; i++){
            p += s;
            p += ch[0];
            p += ch[i];
        }
        
        p += s;
        p += ch[1];
        
        int tmp = press(p);
        
        if(tmp == s.length() + 2){
            s += ch[0];
        } else if(tmp == s.length() + 1){
            s += ch[1];
        } else {
            s += ch[2];
        }
    }
    
    p = "";
    p += s;
    p += ch[0];
    p += s;
    p += ch[1];
    if(press(p) == n){
        p = s + ch[0];
        if(press(p) == n){
            s += ch[0];
        } else {
            s += ch[1];
        }
    } else {
        s += ch[2];        
    }
    
    return s;    
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:40:26: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   40 |     while(s.length() + 2 <= n){
      |           ~~~~~~~~~~~~~~~^~~~
combo.cpp:53:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |         if(tmp == s.length() + 2){
      |            ~~~~^~~~~~~~~~~~~~~~~
combo.cpp:55:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |         } else if(tmp == s.length() + 1){
      |                   ~~~~^~~~~~~~~~~~~~~~~

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