Submission #559000

#	Time	Username	Problem	Language	Result	Execution time	Memory
559000		hollwo_pelw	Bridges (APIO19_bridges)	C++17	100 / 100	2273 ms	133012 KiB

bridges

#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/trie_policy.hpp>
// #include <ext/rope>

using namespace std;
// using namespace __gnu_cxx;
// using namespace __gnu_pbds;

void Hollwo_Pelw();

signed main(){
#ifndef hollwo_pelw_local
	if (fopen("A.inp", "r"))
		assert(freopen("A.inp", "r", stdin)), assert(freopen("A.out", "w", stdout));
#else
	auto start = chrono::steady_clock::now();
#endif
	cin.tie(0), cout.tie(0) -> sync_with_stdio(0);
	int testcases = 1;
	// cin >> testcases;
	for (int test = 1; test <= testcases; test++){
		// cout << "Case #" << test << ": ";
		Hollwo_Pelw();
	}
#ifdef hollwo_pelw_local
	auto end = chrono::steady_clock::now();
	cout << "\nExcution time : " << chrono::duration_cast<chrono::milliseconds> (end - start).count() << "[ms]" << endl;
#endif
}

const int N = 5e4 + 5, M = 1e5 + 5, B = 1000;

int n, m, q, u[M], v[M], w[M], t[M], x[M], y[M];
int change[M], par[N], siz[N], res[M];
vector<pair<int*, int>> st;
vector<int> to_upd[M];

inline int find(int u) { return par[u] == u ? u : find(par[u]); }
inline void merge(int u, int v) {
	if ((u = find(u)) != (v = find(v))) {
		if (siz[u] > siz[v])
			swap(u, v);
		st.emplace_back(par + u, par[u]);
		st.emplace_back(siz + v, siz[v]);
		siz[par[u] = v] += siz[u];
	}
}

inline void rollback(int k) {
	for (; (int) st.size() > k; st.pop_back())
		*st.back().first = st.back().second;
}

void Hollwo_Pelw(){
	cin >> n >> m;
	for (int i = 1; i <= m; i++) {
		cin >> u[i] >> v[i] >> w[i];
	}
	cin >> q;
	for (int i = 1; i <= q; i++) {
		cin >> t[i] >> x[i] >> y[i];
	}

	iota(par + 1, par + n + 1, 1);
	fill(siz + 1, siz + n + 1, 1);

	for (int l = 1, r = min(B, q); l <= q; l += B, r = min(r + B, q)) {
		vector<int> ask, upd, lef;
		fill(change + 1, change + m + 1, 0);
		for (int i = l; i <= r; i++) {
			if (t[i] == 1) {
				change[x[i]] = 1;
				upd.push_back(i);
			} else {
				ask.push_back(i);
			}
		}
		for (int i = 1; i <= m; i++) {
			if (!change[i])
				lef.push_back(i);
		}

		for (int i = l; i <= r; i++) {
			if (t[i] == 1) {
				w[x[i]] = y[i];
			} else {
				for (int j : upd) {
					if (w[x[j]] >= y[i])
						to_upd[i].push_back(x[j]);
				}
			}
		}

		sort(ask.begin(), ask.end(), [&](const int &i, const int &j){ return y[i] > y[j]; });
		sort(lef.begin(), lef.end(), [&](const int &i, const int &j){ return w[i] > w[j]; });

		for (int i = 0, j = 0; i < (int) ask.size(); i++) {
			while (j < (int) lef.size() && w[lef[j]] >= y[ask[i]]) {
				merge(u[lef[j]], v[lef[j]]), j ++;
			}

			
			int k = st.size();
			for (int z : to_upd[ask[i]]) {
				merge(u[z], v[z]);
			}
	
			res[ask[i]] = siz[find(x[ask[i]])];
			rollback(k);
		}

		rollback(0);
	}

	for (int i = 1; i <= q; i++)
		if (t[i] == 2) cout << res[i] << '\n';
}

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