Submission #792823

#	Time	Username	Problem	Language	Result	Execution time	Memory
792823		fatemetmhr	Combo (IOI18_combo)	C++17	5 / 100	1 ms	208 KiB

combo

// Be name khode //

#include "combo.h"
#include <bits/stdc++.h>
 
using namespace std;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

 
#define all(x) x.begin(), x.end()
#define pb     push_back
#define fi     first
#define se     second
#define mp     make_pair
 
typedef long long ll;
 
const int maxn5 = 5e5 + 10;
const int lg    = 20;


string s[4];
char a[4];

std::string guess_sequence(int n) {
    string c[4] = {"A", "B", "X", "Y"};
    shuffle(c, c + 4, rng);
    if(press(c[0]))
        s[0] = s[1] = s[2] = s[3] = c[0];
    else if(press(c[1]))
        s[0] = s[1] = s[2] = s[3] = c[1];
    else if(press(c[2]))
        s[0] = s[1] = s[2] = s[3] = c[2];
    else if(press(c[3]))
        s[0] = s[1] = s[2] = s[3] = c[3];
    for(int i = 0; i < 4; i++)
        a[i] = c[i][0];
    while(s[0].size() < n){
        int keep = s[0].size();
        for(int i = 0; i < 4; i++)
            while(s[i].size() < n)
                s[i].pb(a[rng() % 4]);
        string t = s[0] + s[1] + s[2] + s[3];
        int k = press(t);
        for(int i = 0; i < 4; i++)
            while(s[i].size() > k)
                s[i].pop_back();
        if(k == keep || rng() % 20 == 0){
            int mx = 0, val = 0;
            for(int i = 0; i < 4; i++){
                int w = press(s[i]);
                if(w >= val){
                    mx = i;
                    val = w;
                }
            }
            for(int i = 0; i < 4; i++)
                s[i] = s[mx];
        }
    }
    shuffle(s, s + 4, rng);
    for(int i = 0; i < 4; i++)
        if(press(s[i]) == n)
            return s[i];
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:39:23: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   39 |     while(s[0].size() < n){
      |           ~~~~~~~~~~~~^~~
combo.cpp:42:31: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   42 |             while(s[i].size() < n)
      |                   ~~~~~~~~~~~~^~~
combo.cpp:47:31: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   47 |             while(s[i].size() > k)
      |                   ~~~~~~~~~~~~^~~
combo.cpp:66:1: warning: control reaches end of non-void function [-Wreturn-type]
   66 | }
      | ^

• Subtask 1: 5 / 5
• Subtask 2: 0 / 95