Submission #596769

#	Time	Username	Problem	Language	Result	Execution time	Memory
596769		balbit	Keys (IOI21_keys)	C++17	100 / 100	1399 ms	247528 KiB

keys

#include <vector>
#include <bits/stdc++.h>
#ifndef BALBIT
#include "keys.h"
#endif
using namespace std;
 
#define ll long long
#define pii pair<int, int>
#define f first
#define s second
 
#define REP(i,n) for (int i = 0; i<n; ++i)
#define REP1(i,n) for (int i = 1; i<=n; ++i)
 
#define MX(a,b) a = max(a,b)
#define MN(a,b) a = min(a,b)
#define pb push_back
#define SZ(x) (int)(x).size()
#define ALL(x) (x).begin(), (x).end()
 
#ifdef BALBIT
#define bug(...) cerr<<"#"<<__LINE__<<": "<<#__VA_ARGS__<<"- ", _do(__VA_ARGS__)
template<typename T> void _do(T && x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T && x, S && ...y) {cerr<<x<<", "; _do(y...);}
#else
#define bug(...)
#endif // BALBIT


const int maxn = 3e5+5;
int /*head[maxn], */par[maxn];
// int szedges[maxn]; // size of number of edges left

unordered_map<int, vector<int> > E[maxn]; // edges not done being worked
unordered_set<int> todo[maxn];
unordered_set<int> owned[maxn]; // todo is a subset of owned
vector<int> nhere[maxn]; // nodes in this unordered_set

int find(int x){return x == par[x]? x : par[x] = find(par[x]);}
inline int WHO(int x){return find(x);}

int dead[maxn]; // 1: this head is dead, 2: this head touches a dead, so it's super dead

int getone(int v) {
	while (!todo[v].empty()) {
		int c = *todo[v].begin();
		if (!E[v].count(c)) {
			todo[v].erase(c); continue;
		}
		// bug(v,c,SZ(E[v][c]));
		while (SZ(E[v][c])) {
			int go = WHO(E[v][c].back());
			E[v][c].pop_back();
			if (dead[go]) {
				bug(v, go, "dead!");
				return -2;
			}
			if (go != v) bug(v,go);
			if (go!=v) return go;
		}
		E[v].erase(c); todo[v].erase(c);
	}
	return -1;
}

void mrg(int a, int b, int newhead) {
	if (SZ(nhere[a]) < SZ(nhere[b])) swap(a,b);
	// a is the greater one
	for (int x : owned[b]) {
		if (owned[a].insert(x).s) {
			if (E[a].count(x)) {
				todo[a].insert(x);
			}
		}
	}
	for (auto &p : E[b]) {
		if (owned[a].count(p.f)) todo[a].insert(p.f); // consider merging todo later (?)
		E[a][p.f].insert(E[a][p.f].end(), ALL(p.s));
	}
	nhere[a].insert(nhere[a].end(), ALL(nhere[b]));

	unordered_map<int, vector<int> >().swap(E[b]);
	unordered_set<int>().swap(owned[b]);
	unordered_set<int>().swap(todo[b]);
	vector<int>().swap(nhere[b]);

	if (newhead != a) {
		assert(newhead == b);
		E[a].swap(E[b]);
		owned[a].swap(owned[b]);
		todo[a].swap(todo[b]);
		nhere[a].swap(nhere[b]);
		par[a] = b;
	}else{
		par[b] = a;
	}
}

vector<int> stk;
bool instk[maxn];

void runstack(){
	while (!stk.empty()) {
		int v = stk.back();
		int to = getone(v);
		assert(to != v);
		if (to == -1) {
			dead[v] = 1;
			instk[v] = 0;
			stk.pop_back();
			to = -2;
		}
		if (to == -2) {
			for (int e : stk) {
				dead[e] = 2; 
				instk[e] = 0;
			}
			stk.clear();
			return;
		}
		if (!instk[to]) {
			instk[to] = 1;
			stk.pb(to);
			continue;
		}else{
			while (stk.back() != to) {
				int last = stk.back(); instk[last] = 0; stk.pop_back();
				int pl = stk.back();
				mrg(last, pl, pl);
			}

		}
	}

}

std::vector<int> find_reachable(std::vector<int> r, std::vector<int> u, std::vector<int> v, std::vector<int> c) {
	std::vector<int> ans(r.size(), 1);
	int n = SZ(r);
	int m = SZ(u);

	REP(i,m) {
		int U = u[i], V = v[i], C = c[i];
		REP(barbar, 2) {
			E[U][C].pb(V);
			swap(U,V);
		}
	}

	REP(i,n) {
		par[i] = i;
		nhere[i].pb(i);
		owned[i].insert(r[i]);
		if (E[i].count(r[i])) {
			todo[i].insert(r[i]);
			bug(i, "todo", r[i]);
		}
	}


	REP(i,n) {
		if (!dead[i]) {
			instk[i] = 1;
			stk.pb(i);
			runstack();
		}
	}

	vector<int> raw(n, n+1);

	REP(i,n) {
		int FI = find(i);
		bug(i, dead[i], FI);
		if (FI == i && dead[i] != 2) {
			for (int e : nhere[i]) {
				raw[e] = SZ(nhere[i]);
			}
		}
	}

	REP(i,n) {
		bug(i, raw[i]);
	}

	int mne = *min_element(ALL(raw));
	for (int &e : raw) {
		e = (e==mne?1:0);
	}

	return raw;
}


#ifdef BALBIT
signed main(){
// 	vector<int> yay = find_reachable({0, 1, 1, 2, 2, 1, 2},
// {0, 0, 1, 1, 2, 3, 3, 4, 4, 5},
// {1, 2, 2, 3, 3, 4, 5, 5, 6, 6},
// {0, 0, 1, 0, 0, 1, 2, 0, 2, 1});
	vector<int> yay = find_reachable({0, 0, 0}, {0}, {1}, {0});
	for (int t : yay) bug(t);
}
#endif

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 17 / 17
• Subtask 4: 30 / 30
• Subtask 5: 33 / 33