Submission #1187520

#	Time	Username	Problem	Language	Result	Execution time	Memory
1187520		nouka28	Combo (IOI18_combo)	C++20	30 / 100	150 ms	580 KiB

combo

#include "combo.h"

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

// #define int long long

#define rep(i,n) for(int i=0;i<(n);i++)
#define rng(i,l,r) for(int i=(l);i<(r);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrng(i,l,r) for(int i=(r)-1;i>=(l);i--)

#define fi first
#define se second
#define all(x) (x).begin(),(x).end()

random_device rd;
mt19937 mt(rd());
uniform_int_distribution<int> rnd(0,1000000000);

int randint(int a,int b){
	return a+rnd(mt)%(b-a+1);
}

std::string guess_sequence(int N) {
	string t="ABXY";
	vector<vector<char>> st(N,{'A','B','X','Y'});
	int idx=1;
	string ans="";
	{
		int x=press("AB");
		if(x){
			if(press("A"))ans="A";
			else ans="B";
		}else{
			if(press("X"))ans="X";
			else ans="Y";
		}
	}
	rng(j,1,N){
		st[j].erase(find(all(st[j]),ans[0]));
	}
	while(idx<N){
		string s=ans;
		while(s.size()<N){
			vector<int> vs;
			rep(i,4){
				if(find(all(st[s.size()]),t[i])!=st[s.size()].end()){
					vs.push_back(i);
				}
			}
			s+=t[vs[randint(0,vs.size()-1)]];
		}
		// cout<<"s : "<<s<<endl;
		int ret=press(s);
		// cout<<"ret : "<<ret<<endl;
		rng(i,idx,ret){
			ans+=s[i];
			st[i]={s[i]};
		}
		if(ret!=N){
			st[ret].erase(find(all(st[ret]),s[ret]));
		}
		idx=ret;
	}
	return ans;
}

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