Submission #348147

#	Time	Username	Problem	Language	Result	Execution time	Memory
348147		mariowong	Xylophone (JOI18_xylophone)	C++14	100 / 100	396 ms	620 KiB

xylophone

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

int dif1[5005],dif2[5005],b[5005],pos1,posn;
pair <int,int> a[5005];
bool vis[5005];
void solve(int N) {
	for (int i=2;i<=N;i++){
		dif1[i]=query(i-1,i); 
	}
	for (int i=3;i<=N;i++){
		dif2[i]=query(i-2,i); 
	}
	a[2].first=0;
	a[2].second=1;
	for (int i=3;i<=N;i++){
		if (dif1[i]+dif1[i-1] == dif2[i])
		a[i]=a[i-1];
		else
		{
			a[i].first=a[i-1].second;
			a[i].second=a[i-1].first;
		}
	}
	for (int i=1;i<=N;i++){
		b[1]=i;
		for (int j=1;j<=N;j++){
			vis[j]=false;
		}
		for (int j=2;j<=N;j++){
			if (a[j].first == 1)
			b[j]=b[j-1]+dif1[j];
			else
			b[j]=b[j-1]-dif1[j];
		}
		for (int j=1;j<=N;j++){
			if (b[j] == 1)
			pos1=j;
			if (b[j] == N)
			posn=j;
			if (b[j] < 1 || b[j] > N)
			break;
			if (vis[b[j]])
			break;
			vis[b[j]]=true;
			if (j == N && pos1 < posn)
			goto out;
		}
		
		for (int j=1;j<=N;j++){
			vis[j]=false;
		}
		b[1]=i;
		for (int j=2;j<=N;j++){
			if (a[j].second == 1)
			b[j]=b[j-1]+dif1[j];
			else
			b[j]=b[j-1]-dif1[j];
		}
		for (int j=1;j<=N;j++){
			if (b[j] == 1)
			pos1=j;
			if (b[j] == N)
			posn=j;
			if (b[j] < 1 || b[j] > N)
			break;
			if (vis[b[j]])
			break;
			vis[b[j]]=true;
			if (j == N && pos1 < posn)
			goto out;
		}
	}
	out:;
	for(int i = 1; i <= N; i++) {
		answer(i, b[i]);
	}
}

• Subtask 1: 11 / 11
• Subtask 2: 36 / 36
• Subtask 3: 53 / 53