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Submission #150251

# Submission time Handle Problem Language Result Execution time Memory
150251 2019-09-01T07:59:02 Z ummm(#3574, cerberus, aayush9, knandy) Trip to the Galapagos Islands (FXCUP4_island) C++17
0 / 100
 5000 ms 371812 KB 
#include "island.h"

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

const int MAX_M = 300000;
const int GAP = 1000;

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[MAX_M/GAP+1];

struct UnionFindPathCompression {
	int n;
	vector<int> uf;
	UnionFindPathCompression(int n=0):n(n),uf(n){
		for(int i=0;i<n;++i) 
			uf[i]=i;
	}
	int find(int x){return uf[x] = x==uf[x]?x:find(uf[x]);}
	bool join(int x, int y){
		if((x=find(x))==(y=find(y))) return false;
		uf[y]=x;
		return true;
	}
} UFPC[MAX_M/GAP+1];

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);
	UnionFindPathCompression cur2(K);

	for(int i=0;i<M;++i){
		if(i%GAP==0) UF[i/GAP] = cur, UFPC[i/GAP] = cur2;
		cur.join(edges[i].first, edges[i].second, 0);
		cur2.join(F[edges[i].first], F[edges[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, start = 0, ans = -1;
	for(int i=0;i<M;i+=GAP){
		if(UFPC[i/GAP].find(A) == UFPC[i/GAP].find(B))
			break;
		start = i, bucket = i/GAP;
	}
	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);


	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;
		}
	}
	assert(ans != -1);
	UF[bucket].rollback();
	return memo[A][B] = ans;
}

Subtask #1
0 / 31.0

# Verdict Execution time Memory Grader output
1 Execution timed out 5117 ms 371812 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #2
0 / 39.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 7424 KB Output is correct
2 Correct 11 ms 7424 KB Output is correct
3 Correct 293 ms 251488 KB Output is correct
4 Correct 319 ms 251748 KB Output is correct
5 Runtime error 273 ms 251360 KB Execution killed with signal 11 (could be triggered by violating memory limits)
6 Halted 0 ms 0 KB -

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 7424 KB Output is correct
2 Correct 11 ms 7424 KB Output is correct
3 Execution timed out 5117 ms 371812 KB Time limit exceeded
4 Halted 0 ms 0 KB -