Submission #565617

#	Time	Username	Problem	Language	Result	Execution time	Memory
565617		MrDeboo	Xylophone (JOI18_xylophone)	C++17	100 / 100	65 ms	708 KiB

xylophone

#include "xylophone.h"
#include <bits/stdc++.h>
using namespace std;
void solve(int n){
	int l=1,r=n-1,mid,f=1;
	while(l<=r){
		mid=(l+r)/2;
		if(query(mid,n)==n-1){
			l=mid+1;
			f=mid;
		}else r=mid-1;
	}
	vector<int>v(n+1);
	map<int,bool>mp;
	for(int i=1;i<=n;i++)mp[i]=1;
	v[f]=1;
	v[f+1]=query(f,f+1)+1;
	if(f>1){
		v[f-1]=query(f-1,f)+1;
	}
	for(auto &i:v)mp[i]=0;
	for(int i=f+2;i<=n;i++){
		int k=query(i-1,i);
		if(!mp[v[i-1]+k]){
			v[i]=v[i-1]-k;
			mp[v[i-1]-k]=0;
			continue;
		}
		if(!mp[v[i-1]-k]){
			v[i]=v[i-1]+k;
			mp[v[i-1]+k]=0;
			continue;
		}
		int kk=query(i-2,i);
		if(kk!=abs(v[i-1]-v[i-2])+k){
			if(v[i-1]>v[i-2]){
				v[i]=v[i-1]-k;
				mp[v[i-1]-k]=0;
			}else{
				v[i]=v[i-1]+k;
				mp[v[i-1]+k]=0;
			}
		}else{
			if(v[i-1]<v[i-2]){
				v[i]=v[i-1]-k;
				mp[v[i-1]-k]=0;
			}else{
				v[i]=v[i-1]+k;
				mp[v[i-1]+k]=0;
			}
		}
	}
	for(int i=f-2;i>=1;i--){
		int k=query(i,i+1);
		if(!mp[v[i+1]+k]){
			v[i]=v[i+1]-k;
			mp[v[i+1]-k]=0;
			continue;
		}
		if(!mp[v[i+1]-k]){
			v[i]=v[i+1]+k;
			mp[v[i+1]+k]=0;
			continue;
		}
		int kk=query(i,i+2);
		if(kk!=abs(v[i+1]-v[i+2])+k){
			if(v[i+1]>v[i+2]){
				v[i]=v[i+1]-k;
				mp[v[i+1]-k]=0;
			}else{
				v[i]=v[i+1]+k;
				mp[v[i+1]+k]=0;
			}
		}else{
			if(v[i+1]<v[i+2]){
				v[i]=v[i+1]-k;
				mp[v[i+1]-k]=0;
			}else{
				v[i]=v[i+1]+k;
				mp[v[i+1]+k]=0;
			}
		}
	}
	for(int i=1;i<=n;i++)answer(i,v[i]);
}

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