Submission #439299

#	Time	Username	Problem	Language	Result	Execution time	Memory
439299		CSQ31	Xylophone (JOI18_xylophone)	C++17	100 / 100	172 ms	704 KiB

xylophone

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

void solve(int n){
	vector<int>diff(n+1);
	//diff[i] = A[i]-A[i-1]
	vector<int>res0(n+1),res1(n+1);
	for(int i=1;i<n;i++)res0[i] = query(i,i+1);
	for(int i=1;i<=n-2;i++)res1[i] = query(i,i+2);
	diff[2] = res0[1];
	for(int i=3;i<=n;i++){
		int c = diff[i-1]>0?1:-1;
		if(res0[i-1]+res0[i-2] != res1[i-2])c*=-1;
		diff[i] = c*res0[i-1];
	}
	int p = 1;
	for(int i=2;i<=n;i++){
		diff[i]+=diff[i-1];
		if(diff[i] < diff[p])p = i;
	}
	bool ok = 1;
	set<int>s;
	int con = 1-diff[p];
	vector<int>ans(n+1);
	for(int i=1;i<=n;i++){
		ans[i] = diff[i]+con;
		if(s.count(ans[i]))ok = 0;
		if(ans[i] < 1 || ans[i] > n )ok = 0;
		if(ans[i] == n && i < p)ok = 0;
		s.insert(ans[i]);
	}
	if(!ok){
		con = 1e9;
		for(int i=1;i<=n;i++){
			diff[i]*=-1;
			con = min(diff[i],con);
		}
		con = 1-con;
	}
	for(int i=1;i<=n;i++)answer(i,diff[i]+con);
}

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