Submission #1053979

#	Time	Username	Problem	Language	Result	Execution time	Memory
1053979		pcc	Comparing Plants (IOI20_plants)	C++17	44 / 100	632 ms	57956 KiB

plants

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

#define pii pair<int,int>
#define fs first
#define sc second

const int mxn = 4e5+10;

int arr[mxn];
int N;
int K;
int perm[mxn];
int dp[mxn];
set<int> st;
set<pii> rng;

struct SEG{
#define ls now*2+1
#define rs now*2+2
#define mid ((l+r)>>1)
	pii seg[mxn*4];
	void modify(int now,int l,int r,int s,int e,int v){
		if(l>=s&&e>=r){
			seg[now].sc += v;
			return;
		}
		if(mid>=s)modify(ls,l,mid,s,e,v);
		if(mid<e)modify(rs,mid+1,r,s,e,v);
		seg[now].fs = min(seg[ls].fs+seg[ls].sc,seg[rs].fs+seg[rs].sc);
		return;
	}
	int get_mn(int now,int l,int r){
		if(l == r){
			return l;
		}
		if(seg[ls].fs+seg[ls].sc<seg[rs].fs+seg[rs].sc)return get_mn(ls,l,mid);
		else return get_mn(rs,mid+1,r);
	}
#undef ls
#undef rs
#undef mid
}seg;


void add(int p){
	int nxt = *st.upper_bound(p);
	int pre = *(--st.upper_bound(p));
	rng.erase(pii(nxt-pre,nxt));
	rng.insert(pii(nxt-p,nxt));
	rng.insert(pii(p-pre,p));
	st.insert(p);
	return;
}

void del(int p){
	auto it = st.find(p);
	int pre = *prev(it),nxt = *next(it);
	rng.erase(pii(p-pre,p));
	rng.erase(pii(nxt-p,nxt));
	rng.insert(pii(nxt-pre,nxt));
	st.erase(p);
	return;
}

void calc(int id){
	auto it = rng.rbegin();
	if(it->sc >= N*2)it++;
	auto pos = it->sc;
	pos %= N;
	//cerr<<id<<":"<<pos<<','<<it->fs<<endl;
	assert(it->fs>=K);
	del(pos);
	del(pos+N);
	perm[pos] = id;
	seg.modify(0,0,N*2-1,pos+N-K+1,pos+N,-1);
	seg.modify(0,0,N*2-1,max(pos-K+1,0),pos,-1);
	if(pos-K+1<0)seg.modify(0,0,N*2-1,N*2-1+(pos-K+1)+1,N*2-1,-1);
	while(seg.seg[0].fs+seg.seg[0].sc == 0){
		int p = seg.get_mn(0,0,N*2-1);
		p %= N;
		add(p);
		seg.modify(0,0,N*2-1,p,p,mxn*4);
		add(p+N);
		seg.modify(0,0,N*2-1,p+N,p+N,mxn*4);
	}
	return;
}

void init(int k, std::vector<int> r) {
	K = k;
	N = r.size();
	for(int i = 0;i<N;i++)arr[i] = arr[i+N] = r[i];
	int pre = -1;
	st.insert(-1);
	st.insert(N*2);
	rng.insert(pii(N*2+1,N*2));
	for(int i = 0;i<N*2;i++){
		if(!arr[i]){
			add(i);
		}
		if(arr[i])seg.modify(0,0,N*2-1,i,i,arr[i]);
		else seg.modify(0,0,N*2-1,i,i,mxn*4);
	}
	//cerr<<"INIT!: "<<rng.rbegin()->fs<<endl;
	//for(auto &i:rng)cerr<<i.fs<<','<<i.sc<<endl;
	for(int i = N-1;i>=0;i--)calc(i);
	//for(int i = 0;i<N;i++)cerr<<perm[i]<<',';cerr<<endl;
}

int compare_plants(int x, int y) {
	return perm[x]>perm[y]?1:-1;
}

Compilation message (stderr)

plants.cpp: In function 'void init(int, std::vector<int>)':
plants.cpp:95:6: warning: unused variable 'pre' [-Wunused-variable]
   95 |  int pre = -1;
      |      ^~~

• Subtask 1: 0 / 5
• Subtask 2: 14 / 14
• Subtask 3: 13 / 13
• Subtask 4: 17 / 17
• Subtask 5: 0 / 11
• Subtask 6: 0 / 15
• Subtask 7: 0 / 25