Submission #703035

#	Time	Username	Problem	Language	Result	Execution time	Memory
703035		beepbeepsheep	Xylophone (JOI18_xylophone)	C++17	100 / 100	67 ms	432 KiB

xylophone

#include "xylophone.h"
#include <bits/stdc++.h>
using namespace std;
bool vis[5005];
int arr[5005];
#define ll long long
int eval(ll res, ll res2, ll a, ll b){
	if (a+res==b+res2){
		return 1;
	}
	if (a-res==b-res2){
		return -1;
	}
	if (res==res2){
		if (a<b) return 1;
		else return -1;
	}
	else{
		if (a<b) return 1;
		return -1;
	}
}
void solve(int N) {
	int l=1,r=N,m;
	while (l!=r-1){
		m=(l+r)>>1;
		if (query(m,N)==N-1) l=m;
		else r=m;
	}
	vis[1]=true;
	arr[l]=1;
	if (l==1){
		arr[2]=query(l,l+1)+1;
		vis[arr[2]]=true;
		for (int i=3;i<=N;i++){
			int res=query(i-1,i);
			if (arr[i-1]-res<1 || vis[arr[i-1]-res]){
				arr[i]=res+arr[i-1];
			} else if (res+arr[i-1]>N || vis[res+arr[i-1]]){
				arr[i]=arr[i-1]-res;
			} else{
				int res2=query(i-2,i);
				arr[i]=arr[i-1]+res*eval(res,res2,arr[i-1],arr[i-2]);
			}
			vis[arr[i]]=true;
		}
	}
	else{
		arr[l+1]=query(l,l+1)+1;
		arr[l-1]=query(l-1,l)+1;
		vis[arr[l+1]]=true;
		vis[arr[l-1]]=true;
		for (int i=l+2;i<=N;i++){
			int res=query(i-1,i);
			if (arr[i-1]-res<1 || vis[arr[i-1]-res]){
				arr[i]=res+arr[i-1];
			} else if (res+arr[i-1]>N || vis[res+arr[i-1]]){
				arr[i]=arr[i-1]-res;
			} else{
				int res2=query(i-2,i);
				arr[i]=arr[i-1]+res*eval(res,res2,arr[i-1],arr[i-2]);
			}
			vis[arr[i]]=true;
		}
		for (int i=l-2;i>=1;i--){
			int res=query(i,i+1);
			if (arr[i+1]-res<1 || vis[arr[i+1]-res]){
				arr[i]=res+arr[i+1];
			} else if (res+arr[i+1]>N || vis[res+arr[i+1]]){
				arr[i]=arr[i+1]-res;
			} else{
				int res2=query(i,i+2);
				arr[i]=arr[i+1]+res*eval(res,res2,arr[i+1],arr[i+2]);
			}
			vis[arr[i]]=true;
		}
	}
	//for (int i=1;i<=N;i++) cerr<<arr[i]<<' ';
	for (int i=1;i<=N;i++) answer(i,arr[i]);
}

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