Submission #440289

#	Time	Username	Problem	Language	Result	Execution time	Memory
440289		adamjinwei	Combo (IOI18_combo)	C++14	100 / 100	41 ms	600 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
#define inf 1000000007
#define mod 1000000007
#define rnd() rand_num()
#define bigrnd() dis(rand_num)
//#pragma GCC optimize("Ofast","inline","-ffast-math")
//#pragma GCC target("avx,sse2,sse3,sse4,mmx")
//#define int long long
using namespace std;
unsigned sed=std::chrono::system_clock::now().time_since_epoch().count();
mt19937 rand_num(sed);
uniform_int_distribution<long long> dis(0,inf);
template <typename T> void read(T &x){
	x=0;char ch=getchar();int fh=1;
	while (ch<'0'||ch>'9'){if (ch=='-')fh=-1;ch=getchar();}
	while (ch>='0'&&ch<='9')x=x*10+ch-'0',ch=getchar();
	x*=fh;
}
template <typename T> void write(T x) {
	if (x<0) x=-x,putchar('-');
	if (x>9) write(x/10);
	putchar(x%10+'0');
}
template <typename T> void writeln(T x) {
	write(x);
	puts("");
}
string get(int val)
{
	return (val==1?"A":(val==2?"B":(val==3?"X":"Y")));
}
int res[2005];
string guess_sequence(int n)
{
	int rpl;
	rpl=press("AB");
	if(rpl>=1)
	{
		rpl=press("A");
		if(rpl>=1) res[1]=1;
		else res[1]=2;
	}
	else
	{
		rpl=press("X");
		if(rpl>=1) res[1]=3;
		else res[1]=4;
	}
	string cur;
	cur+=get(res[1]);
	if(n==1) return cur;
	int b=(res[1]==1?2:1);
	int c=(res[1]==b+1?b+2:b+1);
	int d=(res[1]==c+1?c+2:c+1);
	for(int i=2;i<=n-1;++i)
	{
		string ask;
		ask+=cur;
		ask+=get(b);
		ask+=get(b);
		ask+=cur;
		ask+=get(b);
		ask+=get(c);
		ask+=cur;
		ask+=get(b);
		ask+=get(d);
		ask+=cur;
		ask+=get(c);
		rpl=press(ask);
		if(rpl>=i+1) res[i]=b;
		else if(rpl==i) res[i]=c;
		else res[i]=d;
		cur+=get(res[i]);
	}
	string ask;
	ask+=cur;
	ask+=get(b);
	rpl=press(ask);
	if(rpl==n) return ask;
	ask="";
	ask+=cur;
	ask+=get(c);
	rpl=press(ask);
	if(rpl==n) return ask;
	ask="";
	ask+=cur;
	ask+=get(d);
	return ask;
}

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