Submission #75115

#	Time	Username	Problem	Language	Result	Execution time	Memory
75115		Diuven	Combo (IOI18_combo)	C++14	100 / 100	54 ms	464 KiB

combo

#include "combo.h"
using namespace std;

string guess_sequence(int n) {
	string S="AB", R="";
	char Q[5]="ABXY";

	if(press(S)!=0){
		if(press("A")) R+='A';
		else R+='B';
	}
	else{
		if(press("X")) R+='X';
		else R+='Y';
	}
	if(n==1) return R;

	for(int i=0; i<4; i++) if(Q[i]==R[0]){
		swap(Q[i], Q[3]); break; 
	}

	for(int i=2; i<=n-1; i++){
		S.clear();
		for(int j=0; j<3; j++)
			S += R + Q[0] + Q[j];
		S += R + Q[1];

		int now=press(S);
		if(now==i+1) R+=Q[0];
		if(now==i)   R+=Q[1];
		if(now==i-1) R+=Q[2];
	}

	for(int i=0; i<2; i++) if(press(R+Q[i])==n){
		R+=Q[i]; break;
	}
	if((int)R.size()!=n) R+=Q[2];

	return R;
}

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