Submission #120572

#	Time	Username	Problem	Language	Result	Execution time	Memory
120572		tinder	Bridges (APIO19_bridges)	C++14	100 / 100	1730 ms	6804 KiB

bridges

#include <bits/stdc++.h>
using namespace std;

#define v first
#define cost second
#define push_back emplace_back

using ii = pair<int, int>;
const int magic = 400;
const int maxn = 50000 + 5;

int n, m, Q;
int l[maxn << 1], r[maxn << 1], w[maxn << 1];
int ww[maxn << 1];
int par[maxn], sz[maxn];
vector<int> op, id, cost;
int in_buffer[maxn << 1];
int ans[maxn];
vector<int> g[maxn];
vector<int> clr;
vector<int> p, q;
vector<int> ord;

struct List {
	int lst[maxn << 1];
	int ptr;
	List() { ptr = 0; }
	inline void insert(int x) { lst[ptr++] = x; }
	inline void clear() { ptr = 0; }
} xyz;
int vis[maxn];

int find(int u) {
	return par[u] == u ? u : par[u] = find(par[u]);
}
void unite(int u, int v) {
	u = find(u);
	v = find(v);
	if(u == v) return;
	if(sz[u] > sz[v]) swap(u, v);
	sz[v] += sz[u];
	par[u] = v;
}

void dfs(int u, int &res) {
	vis[u] = 1;
	xyz.insert(u);
	res += sz[u];
	for(int v : g[u]) {
		if(!vis[v]) {
			dfs(v, res);
		}
	}
}

void solve() {
	for(int i = 0; i < op.size(); i++) {
		if(op[i] == 1) in_buffer[id[i]] = 1;
	}
	for(int i = 1; i <= n; i++) {
		par[i] = i;
		sz[i] = 1;
	}
	for(int i = 0; i < m; i++) {
		if(!in_buffer[ord[i]]) {
			p.push_back(ord[i]);
		}
	}
	for(int i = 0; i < op.size(); i++) {
		if(op[i] == 1) in_buffer[id[i]] = 0;
		else q.push_back(i);
	}
	sort(q.begin(), q.end(), [&](int x, int y){ return cost[x] > cost[y]; });
	int i = p.size() - 1;
	for(int j : q) {
		while(i >= 0 and w[p[i]] >= cost[j]) {
			unite(l[p[i]], r[p[i]]);
			i--;
		}
		for(int k = 0; k < j; k++) if(op[k] == 1) {
			ww[id[k]] = cost[k];
		}
		int u, v;
		for(int k = 0; k < j; k++) if(op[k] == 1) {
			if(ww[id[k]] >= cost[j]) {
				u = l[id[k]];
				v = r[id[k]];
				u = find(u);
				v = find(v);
				g[u].push_back(v);
				g[v].push_back(u);

				clr.push_back(u);
				clr.push_back(v);
			}
		}
		for(int k = j + 1; k < op.size(); k++) if(op[k] == 1) {
			if(!ww[id[k]]) {
				if(w[id[k]] >= cost[j]) {
					u = l[id[k]];
					v = r[id[k]];
					u = find(u);
					v = find(v);
					g[u].push_back(v);
					g[v].push_back(u);

					clr.push_back(u);
					clr.push_back(v);
				}
			}
		}
		ans[j] = 0;
		dfs(find(id[j]), ans[j]);

		for(int k : clr) g[k].clear();
		for(int k = 0; k < xyz.ptr; k++)
			vis[xyz.lst[k]] = 0;
		clr.clear();
		xyz.clear();
		for(int k = 0; k < j; k++) if(op[k] == 1)
			ww[id[k]] = 0;
	}

	for(int i = 0; i < op.size(); i++) if(op[i] == 1)
		w[id[i]] = cost[i];

	q.clear();
	for(int i = 0; i < op.size(); i++) if(op[i] == 1)
		q.push_back(id[i]);
	sort(q.begin(), q.end());
	q.erase(unique(q.begin(), q.end()), q.end());
	sort(q.begin(), q.end(), [](int x, int y) { return w[x] < w[y]; });

	ord.clear();
	merge(p.begin(), p.end(), q.begin(), q.end(), back_inserter(ord), [](int x, int y){ return w[x] < w[y]; });

	for(int i = 0; i < op.size(); i++) {
		if(op[i] == 2) {
			printf("%d\n", ans[i]);
		}
	}

	p.clear();
	q.clear();
	op.clear();
	id.clear();
	cost.clear();
}

int main(int argc, char const *argv[])
{
	// freopen("in", "r", stdin);
	scanf("%d %d", &n, &m);
	{
		ord.reserve((maxn << 1) + 10);
		p.reserve((maxn << 1) + 10);
		q.reserve((maxn << 1) + 10);
		op.reserve((maxn << 1) + 10);
		id.reserve((maxn << 1) + 10);
		cost.reserve((maxn << 1) + 10);
		clr.reserve((maxn << 1) + 10);
	}
	for(int i = 0; i < m; i++) {
		scanf("%d %d %d", &l[i], &r[i], &w[i]);
		ord.push_back(i);
	}
	sort(ord.begin(), ord.end(), [](int x, int y) { return w[x] < w[y]; } );
	scanf("%d", &Q);
	int done = 0;
	while(Q--) {
		int op, id, cost;
		scanf("%d %d %d", &op, &id, &cost);
		if(op == 1) id--;
		::op.push_back(op);
		::id.push_back(id);
		::cost.push_back(cost);
		if(::op.size() == magic and !done) {
			solve();
		}
	}
	if(op.size()) {
		solve();
	}
	return 0;
}

Compilation message (stderr)

bridges.cpp: In function 'void solve()':
bridges.cpp:57:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < op.size(); i++) {
                 ~~^~~~~~~~~~~
bridges.cpp:69:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < op.size(); i++) {
                 ~~^~~~~~~~~~~
bridges.cpp:97:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int k = j + 1; k < op.size(); k++) if(op[k] == 1) {
                      ~~^~~~~~~~~~~
bridges.cpp:124:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < op.size(); i++) if(op[i] == 1)
                 ~~^~~~~~~~~~~
bridges.cpp:128:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < op.size(); i++) if(op[i] == 1)
                 ~~^~~~~~~~~~~
bridges.cpp:137:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < op.size(); i++) {
                 ~~^~~~~~~~~~~
bridges.cpp: In function 'int main(int, const char**)':
bridges.cpp:153:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
bridges.cpp:164:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d %d", &l[i], &r[i], &w[i]);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:168:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &Q);
  ~~~~~^~~~~~~~~~
bridges.cpp:172:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d %d", &op, &id, &cost);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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