Submission #677536

#	Time	Username	Problem	Language	Result	Execution time	Memory
677536		hello_there_123	Combo (IOI18_combo)	C++17	100 / 100	39 ms	588 KiB

combo

#include<bits/stdc++.h>
//#include "combo.h"
using namespace std;
 
int press(string s);
string guess_sequence(int N){
  string arr[4]={"A","B","X","Y"};
  vector<string>v;
	if(N==1){
		for(int i=0;i<3;i++){
			if(press(arr[i]) == 1) return arr[i];
		}
      return arr[3];
	}
	else{
		string ans = "";
		string start = "";
      	if(press("AB") > 0){
          	if(press("A") == 1) start = "A";
          	else start = "B";
        }
      	else{
          	if(press("X") == 1) start = "X";
          	else start = "Y";
        }
		ans = start;
		for(int i=0;i<4;i++) if(arr[i]!=start) v.push_back(arr[i]);
      	assert(v.size() == 3);
		for(int i=0;i<N-2;i++){
          	int r = ans.length();
			string tr = "";
			tr += ans + v[0];
			tr += ans + v[1] + v[0];
			tr += ans + v[1] + v[1];
			tr += ans + v[1] + v[2];
			int x = press(tr);
			if(x == r) ans+=v[2];
			else if(x == r+1) ans += v[0];
			else ans += v[1];
		}
		if(press(ans+v[0]) == N) return ans+v[0];
		if(press(ans+v[1]) == N) return ans+v[1];
		return ans+v[2];
	}
  	assert(1==0);
	return "";
	
}

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