Submission #124995

#	Time	Username	Problem	Language	Result	Execution time	Memory
124995		streifi	Sightseeing (NOI14_sightseeing)	C++14	25 / 25	2739 ms	104564 KiB

sightseeing

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

const int INF = 0x3f3f3f3f;
const int MAX_V = 500005;

struct adj_edge {
	int v, w;
};

struct list_edge {
	int u, v, w;
	bool operator<(const list_edge &other) const {
		return w < other.w;
	}
};

int V, E, Q;
vector< vector<adj_edge> > adj;
vector<list_edge> edge_list;
int par[MAX_V], dist[MAX_V];

int find(int u) {
	if (par[u] == u)
		return u;
	return par[u] = find(par[u]);
}

void merge(int u, int v) {
	int ru = find(u), rv = find(v);
	if (ru == rv)
		return;
	if (rand()%2)
		swap(ru, rv);
	par[ru] = rv;
}

void kruskall() {
	for (int i = 0; i < V; ++i)
		par[i] = i;
	sort(edge_list.rbegin(), edge_list.rend());
	for (list_edge e: edge_list) {
		if (find(e.u) == find(e.v))
			continue;
		merge(e.u, e.v);
		adj[e.u].push_back({e.v, e.w});
		adj[e.v].push_back({e.u, e.w});
	}
}

void dfs(int cur, int curmin) {
	if (dist[cur] != -1)
		return;
	dist[cur] = curmin;
	for (adj_edge e: adj[cur]) {
		dfs(e.v, min(curmin, e.w));
	}
}

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> V >> E >> Q;
	adj.resize(V);
	edge_list.resize(E);
	for (int e = 0; e < E; ++e) {
		int u, v, q;
		cin >> u >> v >> q;
		edge_list[e] = list_edge{u-1, v-1, q};
	}
	kruskall();
	for (int i = 0; i < V; ++i) {
		dist[i] = -1;
	}
	dfs(0, INF);
	for (int q = 0; q < Q; ++q) {
		int X;
		cin >> X;
		cout << dist[X-1] << "\n";
	}
}

• Subtask 1: 4 / 4
• Subtask 2: 5 / 5
• Subtask 3: 6 / 6
• Subtask 4: 10 / 10