Submission #1149832

#	Time	Username	Problem	Language	Result	Execution time	Memory
1149832		aktilek	Evacuation plan (IZhO18_plan)	C++20	22 / 100	583 ms	193136 KiB

plan

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
#define F first
#define S second
#define pb push_back
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define Fast ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

const int N = 2e5 + 7;
const int R = 1e9 + 10;
const ll INF = 1e18;
const ll MOD = 1e9 + 7;
const int B = 320;

vector < pair < int, int >> g[N];
bool used[N];
ll dist[N];
int l[N], r[N], s[N], t[N];
int par[N], sz[N];
vector < pair < int, int > > kanye[6000000];
int ans[N];

int get(int x) {
	if (par[x] == x) return x;
	return par[x] = get(par[x]);
}

void unite(int x, int y) {
	x = get(x);
	y = get(y);
	if (x == y) return;
	if (sz[x] < sz[y]) swap(x, y);
	sz[x] += sz[y];
	par[y] = x;
}


void solve() {
	int n, m;
	cin >> n >> m;
	
	vector < pair < int, int >> edge;
	
	for (int i = 1; i <= m; i++) {
		int u, v, w;
		cin >> u >> v >> w;
		
		edge.pb({u, v});
		
		g[u].pb({v, w});
		g[v].pb({u, w});
	}
	
	int atom;
	cin >> atom;
	
	for (int i = 1;i <= n; i++) {
		dist[i] = INF;
	}
	
	priority_queue < pair < int, int > > q;
	for (int i = 1; i <= atom; i++) {
		int x;
		cin >> x;
		q.push({0, x});
		dist[x] = 0;
	}
	
	while (q.size()) {
		int a = q.top().S; q.pop();
		
		if (used[a]) continue;
		used[a] = true;
		
		for (auto v : g[a]) {
			int b = v.F, w = v.S;
			if (dist[a] + w < dist[b]) {
				dist[b] = dist[a] + w;
				q.push({-dist[b], b});
			}
		}
	}
	
	vector < pair < int, pair < int, int >>> edges;
	for (int i = 0; i < m; i++) {
		int d = min(dist[edge[i].F], dist[edge[i].S]);
		edges.pb({d, {edge[i].F, edge[i].S}});
	}
	
	sort(rall(edges));
	vector < int > west;
	for (auto ye : edges) {
		// cout << ye.F << ' ' << ye.S.F << ' ' << ye.S.S << '\n';
		kanye[ye.F].pb({ye.S.F, ye.S.S});
		if (west.size() == 0 || west.back() != ye.F) {
			west.pb(ye.F);
		}
	}
	
	// for (int x : west) cout << x << ' ';
	
	int z;
	cin >> z;
	
	for (int i = 1; i <= z; i++) {
		cin >> s[i] >> t[i];
		l[i] = 0, r[i] = int(west.size()) - 1;
	}
	
	int steps = 30;
	while (steps--) {
		vector < int > requests[m + 7];
		
		for (int i = 1; i <= z; i++) {
			if (l[i] > r[i]) continue;
			int mid = (l[i] + r[i]) / 2;
			requests[mid].pb(i);
		}
		
		for (int i = 1; i <= n; i++) {
			par[i] = i;
			sz[i] = 1;
		}
		
		for (int i = 0; i < west.size(); i++) {
			for (auto x : kanye[west[i]]) {
				unite(x.F, x.S);
			}
			
			for (int j : requests[i]) {
				if (get(s[j]) == get(t[j])) {
					ans[j] = west[i];
					r[j] = i - 1;
				} else {
					l[j] = i + 1;
				}
			}
		}
	}
	
	for (int i = 1; i <= z; i++) {
		cout << ans[i] << '\n';
	}
}

int main() {
  	// freopen("gates.in", "r", stdin);
  	// freopen("gates.out", "w", stdout);
  	Fast
  
  	int tc = 1;
  	// cin >> tc;
  
  	while (tc--) {
    	solve();
  	}
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 13
• Subtask 3: 12 / 12
• Subtask 4: 0 / 19
• Subtask 5: 0 / 46