Submission #726796

#	Time	Username	Problem	Language	Result	Execution time	Memory
726796		Cookie	Combo (IOI18_combo)	C++14	100 / 100	51 ms	584 KiB

combo

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
#include <cstdio>
#include <cstdlib>
#include <vector>
#include "combo.h"
const char c[4] = {'A', 'B', 'X', 'Y'};
string guess_sequence(int n){
    string res = "";
    char fir;
    int firstid = -1, secondid = -1;
    int a1 = press("AB"); 
    if(a1 >= 1){
        int a2 = press("A");
        if(a2 > 0){
            res += "A"; fir = 'A';
        }else{
            res += "B"; fir = 'B';
        }
    }else{
        int a2 = press("X");
        if(a2 > 0){
            res += "X"; fir = 'X';
            
        }else{
            res += "Y"; fir = 'Y';
        }
    }
    forr(i, 0, 4){
        if(c[i] != fir){
            if(firstid == -1)firstid = i;
            else if(secondid == -1) secondid = i;
        }
    }
    int thirdid;
    if(fir == 'Y')thirdid = 2;
    else thirdid = 3;
    assert(firstid != secondid && secondid != thirdid);
    for(int i = 1; i < n - 1; i++){
        string guess = "";
        guess += res; guess += c[firstid];
        forr(j, 0, 3){
            guess += res; guess += c[secondid];
            if(!j)guess += c[firstid];
            else if(j == 1)guess += c[secondid];
            else guess += c[thirdid];
        }
        int ans = press(guess);
        
        if(ans == i){
            res += c[thirdid];
        }else if(ans == i + 1){
            res += c[firstid]; 
        }else{
            res += c[secondid];
        }
    }
  	if(n == 1)return(res);
    string guess;
    guess += res; guess += c[firstid]; guess += res; guess += c[secondid];
    int ans = press(guess);
    if(ans == n - 1){
        res += c[thirdid];
    }else{
        guess = res + c[firstid];
        ans = press(guess);
        if(ans == n - 1){
            res += c[secondid];
        }else{
            res += c[firstid];
        }
    }
    
    return(res);
}

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