Submission #445374

#	Time	Username	Problem	Language	Result	Execution time	Memory
445374		silverfish	Combo (IOI18_combo)	C++14	30 / 100	41 ms	572 KiB

combo

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

#define pb push_back


string guess_sequence(int n) {
	srand(time(0));
	string ans="";
	vector<char> c, cc = {'A', 'B', 'X', 'Y'};
	bool found = 0;

	for(int i = 0; i < 3; ++i){
		if(press(ans+cc[i])){
			ans.pb(cc[i]);	
			for(char cch : cc) 
				if(cch != cc[i]) c.pb(cch);
			found = 1;
			break;
		}
	}
	if(!found){
		ans.pb(cc[3]);
		for(char cch : cc) 
			if(cch != cc[3]) c.pb(cch);
	}

	for(int i = 1; i < n; ++i){
		random_shuffle(c.begin(), c.end());
		if(i == n-1){
			int ret = press(ans+c[0]);
			if(ret == i+1){
				ans.pb(c[0]);
			}else{
				ret = press(ans+c[1]);
				if(ret == i+1){
					ans.pb(c[1]);
				}else ans.pb(c[2]);
			}
			break;
		}
		string ask1={c[0],c[0]}, ask2 = {c[0], c[1]};
		int ret = press(ans+ask1+ans+ask2);
		if(ret == i+2){
			ret = press(ans+ask1);
			if(ret == i+2) ans += ask1;
			else ans += ask2;
			++i;
		}else if(ret == i+1){
			ans.pb(c[0]);
			ans.pb(c[2]);
			++i;
		}else{
			ask1 = {c[1], c[0]}, ask2 = {c[1], c[1]};
			ret = press(ans+ask1+ans+ask2);
			if(ret == i+2){
				ret = press(ans+ask1);
				if(ret == i+2) ans += ask1;
				else ans += ask2;
				++i;
			}else if(ret == i+1){
				ans.pb(c[1]);
				ans.pb(c[2]);
				++i;
			}else{
				ans.pb(c[2]);
			}
		}
	}

	return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 25 / 95