Submission #414752

#	Time	Username	Problem	Language	Result	Execution time	Memory
414752		jeqcho	Dancing Elephants (IOI11_elephants)	C++17	0 / 100	9023 ms	332 KiB

elephants

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

typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pair<int,int>> vpi;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define rsz resize
#define sz(x) int(x.size())
#define all(x) begin(x), end(x)
#define fi first
#define se second

int N;
int L;
int const n=5e4+3;
int pre[n];
int nxt[n];
int X[n];
set<pii>st;
int mn;

// subtask 1,2

void init(int N1, int L1, int X1[])
{
	L=L1;
	N = N1;
	F0R(i,N)
	{
		X[i]=X1[i];
		st.insert({X[i],i});
	}
	int prev=-1;
	mn=(*st.begin()).se;
	trav(e,st)
	{
		pre[e.se]=prev;
		if(prev!=-1)nxt[prev]=e.se;
		prev=e.se;
	}
	nxt[(*st.rbegin()).se]=N;
}

int update(int idx, int y)
{
	int prev = pre[idx];
	int next = nxt[idx];
	pre[next]=prev;
	if(prev!=-1)nxt[prev]=next;
	else mn=next;
	st.erase({X[idx],idx});
	next = (*st.upper_bound({y,-1})).se;
	prev = pre[next];
	nxt[idx] = next;
	pre[idx] = prev;
	if(prev!=-1)nxt[prev] = idx;
	else mn=idx;
	pre[next] = idx;
	X[idx]=y;
	st.insert({y,idx});
	int cnt=0;
	int b=-1;
	int cur=mn;
	while(cur!=N)
	{
		if(X[cur]>b)
		{
			++cnt;
			b = X[cur]+L;
		}
		cur=nxt[cur];
	}
	return cnt;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 16
• Subtask 3: 0 / 24
• Subtask 4: 0 / 47
• Subtask 5: 0 / 3