Submission #566070

#	Time	Username	Problem	Language	Result	Execution time	Memory
566070		Bungmint	Bridges (APIO19_bridges)	C++17	100 / 100	1830 ms	9872 KiB

bridges

// Copyright © 2022 Youngmin Park. All rights reserved.
#pragma GCC optimize("O3")
// #pragma GCC target("avx2")
#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
using vpi = vector<pii>;
using pll = pair<ll, ll>;
using vl = vector<ll>;
using vpl = vector<pll>;
using ld = long double;
template <typename T, size_t SZ>
using ar = array<T, SZ>;
template <typename T>
using pqg = priority_queue<T, vector<T>, greater<T>>;

#define all(v) (v).begin(), (v).end()
#define pb push_back
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound

constexpr int INF = 1e9;
constexpr ll LINF = 1e18;
const ld PI = acos((ld)-1.0);
constexpr int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T>
constexpr bool ckmin(T &a, const T &b) { return b < a ? a = b, 1 : 0; }
template <typename T>
constexpr bool ckmax(T &a, const T &b) { return b > a ? a = b, 1 : 0; }

template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p)
{
	return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v)
{
	os << '{';
	string sep;
	for (const T &x : v)
		os << sep << x, sep = ", ";
	return os << '}';
}
template <typename T>
ostream &operator<<(ostream &os, const deque<T> &v) {
	os << vector<T>(all(v));
	return os;
}
template <typename T, typename S, typename C>
ostream &operator<<(ostream &os, priority_queue<T, S, C> pq) {
	vector<T> v;
	while (sz(pq)) {
		v.pb(pq.top());
		pq.pop();
	}
	os << v;
	return os;
}
void dbg_out()
{
	cerr << "\033[0m" << endl;
}
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T)
{
	cerr << ' ' << H;
	dbg_out(T...);
}
#ifdef LOCAL
#define dbg(...) cerr << "\033[1;35m(" << #__VA_ARGS__ << "):\033[33m", dbg_out(__VA_ARGS__)
#else
#define dbg(...) 42
#endif

inline namespace RecursiveLambda
{
	template <typename Fun>
	struct y_combinator_result
	{
		Fun fun_;
		template <typename T>
		explicit y_combinator_result(T &&fun) : fun_(forward<T>(fun)) {}
		template <typename... Args>
		decltype(auto) operator()(Args &&...args)
		{
			return fun_(ref(*this), forward<Args>(args)...);
		}
	};
	template <typename Fun>
	decltype(auto) y_combinator(Fun &&fun)
	{
		return y_combinator_result<decay_t<Fun>>(forward<Fun>(fun));
	}
};

inline namespace Range {
	class ForwardRange {
		int src, dst;

	  public:
	  	explicit constexpr ForwardRange(const int l, const int r) : src(l), dst(r) {}
		explicit constexpr ForwardRange(const int n) : src(0), dst(n) {}
		constexpr ForwardRange begin() const { return *this; }
		constexpr monostate end() const { return {}; }
		constexpr bool operator!=(monostate) const { return src < dst; }
		constexpr void operator++() const {}
		constexpr int operator*() { return src++; }
	};
	class BackwardRange {
		int src, dst;

	  public:
	  	explicit constexpr BackwardRange(const int l, const int r) : src(r), dst(l) {}
		explicit constexpr BackwardRange(const int n) : src(n), dst(0) {}
		constexpr BackwardRange begin() const { return *this; }
		constexpr monostate end() const { return {}; }
		constexpr bool operator!=(monostate) const { return src > dst; }
		constexpr void operator++() const {}
		constexpr int operator*() { return --src; }
	};
	using rep = ForwardRange;
	using per = BackwardRange;
};

// From the USACO tutorial lol
template <int N>
struct DSU {
	int e[N];
	vector<int> mem;
	vector<pair<pii, pii>> ev;
	DSU() { memset(e, -1, sizeof(e)); }

	// get representive component (uses path compression)
	// To use rollback, disable path compression
	inline int get(int x) { return e[x] < 0 ? x : get(e[x]); }
	
	bool same_set(int a, int b) { return get(a) == get(b); }
	
	int size(int x) { return -e[get(x)]; }
	
	bool unite(int x, int y) {  // union by size
		x = get(x), y = get(y);
		if (x == y) return false;
		ev.pb({{x, e[x]}, {y, e[y]}});
		if (e[x] > e[y]) swap(x, y);
		e[x] += e[y]; e[y] = x;
		return true;
	}
	
	void snapshot(){
		mem.pb(sz(ev));
	}
	
	void rollback(){
		if (mem.empty()) return;
		int SZ = mem.back();
		mem.pop_back();
		while(sz(ev) != SZ){
			pair<pii, pii> p = ev.back();
			e[p.fi.fi] = p.fi.se;
			e[p.se.fi] = p.se.se;
			ev.pop_back();
		}
	}

	void clear() {
		memset(e, -1, sizeof(e));
		mem.clear();
		ev.clear();
	}
};



constexpr int SQ = 1000, NN = 1e5 + 100;
bitset<NN> used;
int ans[NN];
vi toJoin[SQ + 100];
int u[NN], v[NN], w[NN];
int ty[NN], id[NN], ww[NN];
DSU<NN> dsu{};

void solve()
{
	int n, m;
	cin >> n >> m;
	for (int i : rep(m)) {
		cin >> u[i] >> v[i] >> w[i];
		u[i]--, v[i]--;
	}
	int q;
	cin >> q;
	for (int i : rep(q)) {
		cin >> ty[i] >> id[i] >> ww[i];
		id[i]--;
	}
	for (int L = 0; L < q; L += SQ) {
		vi upd, calc, unchanged;
		dsu.clear();
		int R = min(L + SQ - 1, q - 1);
		for (int i : rep(L, R + 1)) {
			if (ty[i] == 1) upd.pb(i), used[id[i]] = 1;
			else calc.pb(i);
		}
		for (int j : rep(m)) {
			if (!used[j]) unchanged.pb(j);
		}
		for (int j : rep(L, R + 1)) {
			if (ty[j] == 1) {
				w[id[j]] = ww[j];
			}else{
				toJoin[j - L].clear();
				for (auto &e : upd) {
					if (w[id[e]] >= ww[j]) toJoin[j - L].pb(id[e]);
				}
			}
		}
		sort(all(calc), [&](auto x, auto y) {
			return ww[x] > ww[y];
		});
		sort(all(unchanged), [&](auto x, auto y) {
			return w[x] > w[y];
		});
		int ptr = 0;
		for (auto &e : calc) {
			while (ptr < sz(unchanged) && w[unchanged[ptr]] >= ww[e]) {
				dsu.unite(u[unchanged[ptr]], v[unchanged[ptr]]);
				ptr++;
			}
			dsu.snapshot();
			for (auto &f : toJoin[e - L]) {
				dsu.unite(u[f], v[f]);
			}
			ans[e] = dsu.size(id[e]);
			dsu.rollback();
		}
		for (auto &e : upd) used[id[e]] = 0;
	}
	for (auto &e : ans) {
		if (e) cout << e << '\n';
	}	
}

int main()
{
	cin.tie(0)->sync_with_stdio(0);
	cin.exceptions(cin.failbit);
	int testcase = 1;
	// cin >> testcase;
	while (testcase--)
	{
		solve();
	}
#ifdef LOCAL
	cerr << "Time elapsed: " << 1.0 * (double)clock() / CLOCKS_PER_SEC << " s.\n";
#endif
}

• Subtask 1: 13 / 13
• Subtask 2: 16 / 16
• Subtask 3: 17 / 17
• Subtask 4: 14 / 14
• Subtask 5: 13 / 13
• Subtask 6: 27 / 27