Submission #229221

#	Time	Username	Problem	Language	Result	Execution time	Memory
229221		monus1042	Combo (IOI18_combo)	C++17	100 / 100	40 ms	624 KiB

combo

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

string guess_sequence(int N) {
	string S="";
	if (N==1){
		string tot="ABX";
		for (int i=0; i<3; i++){
			string x;
			x+=tot[i];
			int c=press(x);
			if (c==1){
				return x;
			}
		}
		return "Y";
	}
	string aux="ABX";
	int c=press(aux);
	if (!c){
		S+="Y";
	}else if (N>=3 && c==3){
		S+="A";
	}else if (c==2){
		int p1=press("AB");
		if (p1==2){
			S+="A";
		}else{
			S+="B";
		}
	}else if (c==1){
		int p1=press("BYBA");
		if (!p1){
			S+="X";
		}else if (p1==2){
			S+="B";
		}else S+="A";
	}

	string total="ABXY";
	string usingthis="";
	for (int i=0; i<4; i++){
		if (S[0]==total[i]) continue;
		usingthis.push_back(total[i]);
		//cout<<total[i];
	}
	//cout<<endl;
	
	int matches=1;
	for (int i=2; i<=N-1; i++){
		string send=S, s1, s2, s3, s4;
		s1=s2=s3=s4="";
		
		s1+=usingthis[0];
		
		s2+=usingthis[1];
		s2+=usingthis[0];

		s3+=usingthis[1];
		s3+=usingthis[1];

		s4+=usingthis[1];
		s4+=usingthis[2];

		send = send + s1 + S + s2 + S + s3 + S + s4;
		//cout<<send<<endl;
		// ch
		int p1=press(send);
		//cout<<p1<<endl;
		if (p1 == matches){
			S+=usingthis[2];
		}else if (p1 == matches + 2){
			S+=s4;
			S.pop_back();
		}else{
			S+=s1;
		}
		matches++;
	}

	//special case i==N:
	string send=S;
	send+=usingthis[0];
	send+=S;
	send+=usingthis[1];
	int p1=press(send);
	if (p1 == matches){
		S+=usingthis[2];
	}else{
		string la=S + usingthis[0];
		int p2=press(la);
		if (p2 == matches + 1){
			S+=usingthis[0];
		}else{
			S+=usingthis[1];
		}
	}
	//cout<<S<<endl;
	//cout<<N<<'\n';
	return S;
}

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