Submission #670979

#	Time	Username	Problem	Language	Result	Execution time	Memory
670979		75_yabuki	Combo (IOI18_combo)	C++14	100 / 100	29 ms	552 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
vector<char> cand = {'A', 'B', 'X', 'Y'};
vector<char> V;

std::string guess_sequence(int N) {
	std::string S = "";
    if(press("AB")){
        if(press("A")) S = "A"; 
        else S = "B";
    }
    else{
        if(press("X")) S = "X"; 
        else S = "Y";
    }	
    
	if(N == 1) return S;
	
	for(auto v : cand){
		if(v == S[0]) continue;
        else V.push_back(v);
	}
    
    // for(auto v : V) cout << v << endl;
    
    while((int) S.size() < N-1){
        string query = S + V[0] + S + V[1] + V[0] + S + V[1] + V[1] + S + V[1] + V[2]; // SXSYBSYXSYY
        int ret = press(query);
        if(ret == (int) S.size()) S += V[2];
        else if(ret == (int) S.size() + 1) S += V[0];
        else S += V[1];
    }
	
    if(press(S + V[0]) == N){
        S += V[0];
    }
    else if(press(S + V[1]) == N){
        S += V[1];
    }
    // else return S + V[2];
    else S += V[2];
    
    // cout << S << endl;
    return S;
}

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