Submission #494433

#	Time	Username	Problem	Language	Result	Execution time	Memory
494433		jjang36524	Bridges (APIO19_bridges)	C++14	14 / 100	3069 ms	21308 KiB

bridges

#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,fma")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define MAX 201010
#define MAXS 20
#define INF 1000000000000000001
#define bb ' '
#define ln '\n'
#define Ln '\n'
#define B 1000
struct dsu {
	vector<vector<ll>> p, num;
	vector<ll> chk;
	ll qnum = 0;
	dsu(ll N) {
		p.resize(2);
		num.resize(2);
		p[0].resize(N + 1);
		p[1].resize(N + 1);
		num[0].resize(N + 1);
		num[1].resize(N + 1);
		ll i;
		for (i = 1; i <= N; i++) p[0][i] = i, num[0][i] = 1;
	}
	ll find(ll v) {
		if (!p[qnum][v]) {
			p[qnum][v] = p[0][v];
			chk.push_back(v);
		}
		if (p[qnum][v] == v) return v;
		else return p[qnum][v] = find(p[qnum][v]);
	}
	ll get(ll v) {
		v = find(v);
		if (!num[qnum][v]) {
			num[qnum][v] = num[0][v];
			chk.push_back(v);
		}
		return num[qnum][v];
	}
	void uni(ll a, ll b) {
		a = find(a);
		b = find(b);
		if (a == b) return;
		if (get(b) < get(a)) swap(a, b);
		ll x = get(b) + get(a);
		p[qnum][a] = b;
		num[qnum][b] = x;
		if (qnum == 1) chk.push_back(b), chk.push_back(a);
	}
	void rb() {
		for (auto x : chk) { num[1][x] = p[1][x] = 0; }
		chk.clear();
		qnum = 0;
	}
	void mark() {
		qnum++;
	}
};
struct query {
	ll t;
	ll b, r, s, w;
	ll ind;
	query(ll t, ll x, ll y, ll ind) :ind(ind) {
		query::t = t;
		if (t == 1) b = x, r = y;
		else s = x, w = y;
	}
	query() {}
};
vector<pll> edge;
ll val[MAX];
vector<query> qv[2000];
query qarr[MAX];
ll ans[MAX];
ll chk[MAX];
ll nchk[MAX];
bool cmp(query& a, query& b) {
	return a.w > b.w;
}
signed main() {
	ios::sync_with_stdio(false), cin.tie(0);
	ll N, M;
	cin >> N >> M;
	ll i;
	edge.resize(M + 1);
	for (i = 1; i <= M; i++) {
		ll a, b;
		cin >> a >> b >> val[i];
		edge[i] = { a, b };
	}
	ll Q;
	cin >> Q;
	for (i = 1; i <= Q; i++) {
		ll a, b, c;
		cin >> a >> b >> c;
		qarr[i] = query(a, b, c, i);
		qv[(i - 1) / B].push_back(qarr[i]);
	}
	ll st, en;
	set<pll> est;
	for (i = 1; i <= M; i++) est.emplace(-val[i], i);
	for (i = 0; ; i++) {
		st = 1 + i * B;
		en = (1 + i) * B;
		en = min(en, Q);
		if (st > en) break;
		ll j;
		for (j = st; j <= en; j++) if (qarr[j].t == 1) chk[qarr[j].b] = 1;
		vector<query> qq;
		for (auto& q : qv[i]) if (q.t == 2) qq.push_back(q);
		if (qq.size()) sort(qq.begin(), qq.end(), cmp);
		dsu d(N);
		set<pll>::iterator it;
		it = est.begin();
		for (ll j = 0; j < qq.size(); j++) {
			for (; it != est.end(); it++) {
				if (chk[it->second]) continue;
				if (qq[j].w > -it->first) break;
				else d.uni(edge[it->second].first, edge[it->second].second);
			}
			d.mark();
			ll cnt = 0;
			for (ll k = qq[j].ind; k >= st; k--) {
				if (qarr[k].t == 1) {
					if (qarr[k].r >= qq[j].w && !nchk[qarr[k].b]) {
						d.uni(edge[qarr[k].b].first, edge[qarr[k].b].second);
						nchk[qarr[k].b] = 1;
					}
				}
			}
			for (ll k = en; k > qq[j].ind; k--) {
				if (qarr[k].t == 1) {
					if (!nchk[qarr[k].b] && val[qarr[k].b] >= qq[j].w) {
						d.uni(edge[qarr[k].b].first, edge[qarr[k].b].second);
						nchk[qarr[k].b] = 1;
					}
				}
			}
			for (ll k = en; k >= st; k--) if (qarr[k].t == 1) nchk[qarr[k].b] = 0;
			ans[qq[j].ind] = d.get(qq[j].s);
			d.rb();
		}
		for (j = st; j <= en; j++) {
			if (qarr[j].t == 1) {
				chk[qarr[j].b] = 0;
				est.erase({ -val[qarr[j].b], qarr[j].b });
				est.emplace(-qarr[j].r, qarr[j].b);
				val[qarr[j].b] = qarr[j].r;
			}
		}
	}
	for (i = 1; i <= Q; i++) if (ans[i]) cout << ans[i] << ln;
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:125:20: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<query>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |   for (ll j = 0; j < qq.size(); j++) {
      |                  ~~^~~~~~~~~~~
bridges.cpp:132:7: warning: unused variable 'cnt' [-Wunused-variable]
  132 |    ll cnt = 0;
      |       ^~~

• Subtask 1: 0 / 13
• Subtask 2: 0 / 16
• Subtask 3: 0 / 17
• Subtask 4: 14 / 14
• Subtask 5: 0 / 13
• Subtask 6: 0 / 27