Submission #64607

#	Time	Username	Problem	Language	Result	Execution time	Memory
64607		zscoder	Xylophone (JOI18_xylophone)	C++17	100 / 100	451 ms	992 KiB

xylophone

#include "xylophone.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
#define fi first
#define se second
#define mp make_pair
#define pb push_back
 
typedef long long ll;
typedef pair<ll,ll> ii;
typedef vector<int> vi;
typedef long double ld; 
typedef tree<ii, null_type, less<ii>, rb_tree_tag, tree_order_statistics_node_update> pbds;

static int D[5111];
static int D2[5111];
static int change[5111];

int ask(int l, int r)
{
	l++; r++;
	return query(l,r);
}

void out(vector<int> &v)
{
	for(int i=0;i<v.size();i++)
	{
		answer(i+1,v[i]+1);
	}
}

bool valid(vector<int> &v)
{
	bool ok=0;
	for(int i=0;i<v.size();i++)
	{
		if(v[i]==0) ok=1;
		if(!ok&&v[i]==int(v.size())-1) return false;
		if(v[i]<0||v[i]>=int(v.size())) return false;
	}
	return true;
}

void solve(int N) 
{
	vector<int> A(N);
	for(int i=0;i+1<N;i++)
	{
		D[i] = ask(i,i+1);
		if(i+2<N) D2[i] = ask(i,i+2);
	}
	for(int i=2;i<N;i++)
	{
		if(D[i-2]+D[i-1]==D2[i-2])
		{
			change[i] = 0;
		}
		else
		{
			change[i] = 1;
		}
	}
	for(int i=0;i<N;i++)
	{
		for(int j=0;j<2;j++)
		{
			vi V(N);
			V[0] = i; int cur = j;
			for(int k=1;k<N;k++)
			{
				if(cur) V[k]=V[k-1]+D[k-1];
				else V[k]=V[k-1]-D[k-1];
				if(k+1<N&&change[k+1]) cur^=1;
			}
			if(valid(V)) {out(V); return ;}
		}
	}
}

Compilation message (stderr)

xylophone.cpp: In function 'void out(std::vector<int>&)':
xylophone.cpp:32:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<v.size();i++)
              ~^~~~~~~~~
xylophone.cpp: In function 'bool valid(std::vector<int>&)':
xylophone.cpp:41:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<v.size();i++)
              ~^~~~~~~~~

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