Submission #168393

#	Time	Username	Problem	Language	Result	Execution time	Memory
168393		qkxwsm	Bridges (APIO19_bridges)	C++14	44 / 100	3055 ms	9624 KiB

bridges

#include <bits/stdc++.h>

using namespace std;

template<class T, class U>
void ckmin(T &a, U b)
{
	if (a > b) a = b;
}
template<class T, class U>
void ckmax(T &a, U b)
{
	if (a < b) a = b;
}

#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)
#define SZ(x) ((int) ((x).size()))
#define ALL(x) (x).begin(), (x).end()
#define MAXN 100013
#define MAGIC 1000

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpi;
typedef vector<pll> vpl;

int N, M, Q;
pii edge[MAXN];
int weight[MAXN], tmp[MAXN];
array<int, 3> quer[MAXN];
vector<array<int, 3> > events;
bitset<MAXN> mentioned, vis;
vi edge1[MAXN];
vi inds;
int dsu[MAXN], siz[MAXN], ans[MAXN];

int get(int u)
{
	return (u == dsu[u] ? u : dsu[u] = get(dsu[u]));
}
void merge(int u, int v)
{
	u = get(u);
	v = get(v);
	if (u == v) return;
	if (siz[v] > siz[u]) swap(u, v);
	dsu[v] = u;
	siz[u] += siz[v];
	siz[v] = 0;
}

int32_t main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	cout << fixed << setprecision(12);
	cerr << fixed << setprecision(4);
	cin >> N >> M;
	FOR(i, 0, M)
	{
		int u, v, d;
		cin >> u >> v >> d;
		u--; v--;
		if (u > v) swap(u, v);
		edge[i] = {u, v};
		weight[i] = d;
	}
	cin >> Q;
	FOR(i, 0, Q)
	{
		int a, b, c;
		cin >> a >> b >> c; b--;
		if (a == 2)
		{
			quer[i] = {-1, b, c};
		}
		else
		{
			quer[i] = {b, weight[b], c};
			weight[b] = c;
		}
	}
	FORD(i, Q, 0)
	{
		if (quer[i][0] == -1) continue;
		int idx = quer[i][0];
		weight[idx] = quer[i][1];
	}
	for (int i = 0; i < Q; i += MAGIC)
	{
		FOR(j, 0, N)
		{
			dsu[j] = j;
			siz[j] = 1;
		}
		mentioned.reset();
		inds.clear();
		events.clear();
		for (int j = i; j < i + MAGIC && j < Q; j++)
		{
			if (quer[j][0] == -1) continue;
			mentioned[quer[j][0]] = true;
		}
		FOR(j, 0, M)
		{
			if (mentioned[j])
			{
				inds.PB(j);
			}
			else
			{
				events.PB({weight[j], 1, j});
			}
		}
		for (int j = i; j < i + MAGIC && j < Q; j++)
		{
			if (quer[j][0] != -1) continue;
			events.PB({quer[j][2], 0, j});
		}
		sort(ALL(events), greater<array<int, 3> >());
		for (auto e : events)
		{
			int idx = e[2];
			if (e[1] == 1)
			{
				merge(edge[idx].fi, edge[idx].se);
			}
			else
			{
				for (int x : inds)
				{
					tmp[x] = weight[x];
				}
				FOR(j, i, idx)
				{
					if (quer[j][0] == -1) continue;
					tmp[quer[j][0]] = quer[j][2];
				}
				for (int x : inds)
				{
					if (tmp[x] >= quer[idx][2])
					{
						int u = get(edge[x].fi), v = get(edge[x].se);
						if (u == v) continue;
						edge1[u].PB(v);
						edge1[v].PB(u);
					}
				}
				int s = get(quer[idx][1]);
				vi q; q.PB(s);
				vis[s] = true;
				while(!q.empty())
				{
					int u = q.back(); q.pop_back();
					ans[idx] += siz[u];
					for (int v : edge1[u])
					{
						if (!vis[v])
						{
							vis[v] = true;
							q.PB(v);
						}
					}
				}
				for (int x : inds)
				{
					if (tmp[x] >= quer[idx][2])
					{
						int u = get(edge[x].fi), v = get(edge[x].se);
						edge1[u].clear();
						edge1[v].clear();
						vis[u] = false;
						vis[v] = false;
					}
				}
				vis[s] = false;
			}
		}
		for (int j = i; j < i + MAGIC && j < Q; j++)
		{
			if (quer[j][0] == -1) continue;
			weight[quer[j][0]] = quer[j][2];
		}
	}
	FOR(i, 0, Q)
	{
		if (quer[i][0] != -1) continue;
		cout << ans[i] << '\n';
	}
	return 0;
}

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