Submission #1033771

#	Time	Username	Problem	Language	Result	Execution time	Memory
1033771		emptypringlescan	Xylophone (JOI18_xylophone)	C++17	100 / 100	40 ms	592 KiB

xylophone

#include <bits/stdc++.h>
using namespace std;
#include "xylophone.h"
void solve(int n){
	int lo=1,hi=n-1,mid;
	while(lo<hi){
		mid=(lo+hi+1)/2;
		int x=query(mid,n);
		if(x==n-1) lo=mid;
		else hi=mid-1;
	}
	int ans[n+1],got[n+1];
	memset(got,0,sizeof(got));
	memset(ans,-1,sizeof(ans));
	ans[lo]=1;
	got[1]=1;
	if(lo>1) ans[lo-1]=1+query(lo-1,lo);
	for(int i=lo-2; i>0; i--){
		int x=query(i,i+1);
		int a=ans[i+1]+x,b=ans[i+1]-x;
		if(a<=1||a>=n||got[a]) ans[i]=b;
		else if(b<=1||b>=n||got[b]) ans[i]=a;
		else{
			int y=query(i,i+2);
			if(y==abs(ans[i+1]-ans[i+2])){
				if(ans[i+1]<ans[i+2]) ans[i]=a;
				else ans[i]=b;
			}
			else if(b==max(ans[i+1],ans[i+2])-y) ans[i]=b;
			else ans[i]=a;
		}
		got[ans[i]]=1;
	}
	ans[lo+1]=1+query(lo,lo+1);
	for(int i=lo+2; i<=n; i++){
		int x=query(i-1,i);
		int a=ans[i-1]+x,b=ans[i-1]-x;
		if(a<=1||a>n||got[a]) ans[i]=b;
		else if(b<=1||b>n||got[b]) ans[i]=a;
		else{
			int y=query(i-2,i);
			if(y==abs(ans[i-1]-ans[i-2])){
				if(ans[i-1]<ans[i-2]) ans[i]=a;
				else ans[i]=b;
			}
			else if(b==max(ans[i-1],ans[i-2])-y) ans[i]=b;
			else ans[i]=a;
		}
		got[ans[i]]=1;
	}
	for(int i=1; i<=n; i++) answer(i,ans[i]);
}

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