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Submission #151091

# Submission time Handle Problem Language Result Execution time Memory
151091 2019-09-01T17:23:29 Z aayush9 Trip to the Galapagos Islands (FXCUP4_island) C++17
31 / 100
 5000 ms 490792 KB 
#include "island.h"
 
#include <bits/stdc++.h>
using namespace std;
 
const int MAX_M = 300000;
const int GAP = 500;
 
struct UnionFind {
	int n;
	vector<int> uf,si,c;
	UnionFind(int n=0):n(n),uf(n),si(n,1){
		for(int i=0;i<n;++i) 
			uf[i]=i;
	}
	int find(int x){return x==uf[x]?x:find(uf[x]);}
	bool join(int x, int y, bool keep_track = 1){
		if((x=find(x))==(y=find(y))) return false;
		if(si[x]<si[y]) swap(x,y);
		si[x]+=si[y];uf[y]=x;
		if(keep_track) c.push_back(y);
		return true;
	}
	void rollback(){
		while(c.size()){
			int x=c.back(); c.pop_back();
			si[uf[x]]-=si[x];uf[x]=x;;
		}
	}
} UF[603];
 
struct UnionFindFinches{
	int n;
	vector<int> si,uf;
	vector<vector<pair<int,int>>> adj;
	UnionFindFinches(int n=0):n(n),si(n,1),uf(n),adj(n){
		for(int i=0;i<n;++i) uf[i]=i;
	}
	int find(int x){
		if(x==uf[x]) return x;
		return find(uf[x]);
	}
	void join(int x, int y, int time, int special){
		if((x=find(x))==(y=find(y))) return;
		
		if(y == special || x != special){
			if(si[x]<si[y]) swap(x,y);
			si[x]+=si[y];
		}

		uf[y]=x;


		adj[x].push_back({y,time});
	}
};
 
vector<pair<int,int>> edges;
vector<int> pos[100005];
 
int M, N;
 
map<int,int> memo[100005];
 
void Init(int K, vector<int> F, vector<int> S, vector<int> E){
	N = F.size(), M = S.size();
 
	edges.resize(M);
	for(int i=0;i<N;++i) memo[i].clear();
	for(int i=0;i<K;++i) pos[i].clear();
 
	for(int i=0;i<M;++i) edges[M-i-1] = {S[i], E[i]};
 
	for(int i=0;i<(int)F.size();++i)
		pos[F[i]].push_back(i);
 
	UnionFind cur(N);
 
	for(int i=0;i<M;++i){
		if(i%GAP==0) UF[i/GAP] = cur;
		cur.join(edges[i].first, edges[i].second, 0);
	}

	for(int finch=0;finch<K;++finch) if(pos[finch].size() > 60*GAP){
		UnionFindFinches dsu(N);

		for(auto i:pos[finch]) dsu.join(pos[finch][0], i, -1, pos[finch][0]);
 
		for(int i=0;i<M;++i){
			int x, y; tie(x,y) = edges[i];
			if(F[x] == finch && F[y] == finch) continue;
			if(F[y] == finch) swap(x,y);
			dsu.join(x,y,M - i,pos[finch][0]);
		}


		function<void(int,int)> dfs = [&](int y, int min_so_far){
			memo[finch][F[y]] = max(memo[finch][F[y]], min_so_far);
			for(auto i:dsu.adj[y]) dfs(i.first, min(min_so_far,i.second));
		};
		for(auto i:dsu.adj[pos[finch][0]])
			dfs(i.first, i.second);
		// for(auto i:dsu.who[pos[finch][0]])
		// 	memo[finch][F[i.first]] = max(memo[finch][F[i.first]], i.second);
	}
}
 
int Separate(int A, int B){
	if(A>B) swap(A,B);
	if(memo[A].count(B)) return memo[A][B];
 
	int bucket = 0, ans = -1;
 
	int lo = 0, hi = (M-1)/GAP;
	while(lo<hi){
		int b = (lo + hi + 1)/2;
 
		for(auto i:pos[A]) UF[b].join(pos[A][0], i, 1);
		for(auto i:pos[B]) UF[b].join(pos[B][0], i, 1);
 
		if(UF[b].find(pos[A][0]) == UF[b].find(pos[B][0])){
			hi = b - 1;
		}
		else{
			lo = b;
		}
		UF[b].rollback();
	}
 
	bucket = lo;
 
	for(auto i:pos[A]) UF[bucket].join(pos[A][0], i, 1);
	for(auto i:pos[B]) UF[bucket].join(pos[B][0], i, 1);
 
	int start = bucket * GAP;
 
	for(int i=start;i<=start+GAP && i<M; ++i){
		UF[bucket].join(edges[i].first, edges[i].second, 1);
		if(UF[bucket].find(pos[A][0]) == UF[bucket].find(pos[B][0])){
			ans = M - i;
			break;
		}
	}
	UF[bucket].rollback();
	return memo[A][B] = ans;
}

Subtask #1
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 2963 ms 488908 KB Output is correct
2 Correct 3083 ms 488932 KB Output is correct
3 Correct 3039 ms 488776 KB Output is correct
4 Correct 3029 ms 488992 KB Output is correct
5 Correct 3032 ms 488804 KB Output is correct
6 Correct 3189 ms 488888 KB Output is correct
7 Correct 3231 ms 488852 KB Output is correct
8 Correct 3155 ms 488888 KB Output is correct
9 Correct 3055 ms 488848 KB Output is correct
10 Correct 3221 ms 488912 KB Output is correct

Subtask #2
0 / 39.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB Output is correct
2 Correct 8 ms 7420 KB Output is correct
3 Correct 558 ms 490792 KB Output is correct
4 Correct 806 ms 486448 KB Output is correct
5 Correct 1319 ms 486260 KB Output is correct
6 Correct 2500 ms 486168 KB Output is correct
7 Correct 4981 ms 486216 KB Output is correct
8 Execution timed out 5131 ms 486268 KB Time limit exceeded
9 Halted 0 ms 0 KB -

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB Output is correct
2 Correct 8 ms 7420 KB Output is correct
3 Correct 2963 ms 488908 KB Output is correct
4 Correct 3083 ms 488932 KB Output is correct
5 Correct 3039 ms 488776 KB Output is correct
6 Correct 3029 ms 488992 KB Output is correct
7 Correct 3032 ms 488804 KB Output is correct
8 Correct 3189 ms 488888 KB Output is correct
9 Correct 3231 ms 488852 KB Output is correct
10 Correct 3155 ms 488888 KB Output is correct
11 Correct 3055 ms 488848 KB Output is correct
12 Correct 3221 ms 488912 KB Output is correct
13 Correct 558 ms 490792 KB Output is correct
14 Correct 806 ms 486448 KB Output is correct
15 Correct 1319 ms 486260 KB Output is correct
16 Correct 2500 ms 486168 KB Output is correct
17 Correct 4981 ms 486216 KB Output is correct
18 Execution timed out 5131 ms 486268 KB Time limit exceeded
19 Halted 0 ms 0 KB -