oj.uz

Submission #521367

# Submission time Handle Problem Language Result Execution time Memory
521367 2022-02-02T01:12:09 Z penguinhacker Valley (BOI19_valley) C++14
100 / 100
 212 ms 42160 KB 
#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ar array

const int mxN=1e5;
const ll INF=1e18;
int n, ns, q, ed, tin[mxN], tout[mxN], t, anc[mxN][17];
ar<int, 3> edge[mxN];
vector<ar<int, 2>> adj[mxN];
ll d[mxN], dp[mxN], lft[mxN][17];
bool shop[mxN];

void dfs1(int u=ed) {
	tin[u]=t++;
	dp[u]=shop[u]?0:INF;
	for (int i=1; i<17; ++i)
		anc[u][i]=anc[u][i-1]^-1?anc[anc[u][i-1]][i-1]:-1;
	for (ar<int, 2> v : adj[u]) {
		anc[v[0]][0]=u;
		adj[v[0]].erase(find(adj[v[0]].begin(), adj[v[0]].end(), ar<int, 2>{u, v[1]}));
		d[v[0]]=d[u]+v[1];
		dfs1(v[0]);
		dp[u]=min(dp[u], dp[v[0]]+v[1]);
	}
	tout[u]=t++;
	lft[u][0]=dp[u]<INF?dp[u]-d[u]:INF;
}

bool ia(int u, int v) {
	return tin[u]<=tin[v]&&tout[v]<=tout[u];
}

void dfs2(int u=ed) {
	for (int i=1; i<17; ++i)
		lft[u][i]=min(lft[u][i-1], anc[u][i-1]^-1?lft[anc[u][i-1]][i-1]:INF);
	for (ar<int, 2> v : adj[u])
		dfs2(v[0]);
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n >> ns >> q >> ed, --ed;
	for (int i=1; i<n; ++i) {
		int u, v, w;
		cin >> u >> v >> w, --u, --v;
		edge[i]={u, v, w};
		adj[u].push_back({v, w});
		adj[v].push_back({u, w});
	}
	while(ns--) {
		int u;
		cin >> u, --u;
		shop[u]=1;
	}
	anc[ed][0]=-1;
	dfs1();
	dfs2();
	while(q--) {
		int I, u;
		cin >> I >> u, --u;
		int a=edge[I][0], b=edge[I][1];
		if (d[a]>d[b])
			swap(a, b);
		if (!ia(b, u)) {
			cout << "escaped\n";
		} else {
			int v=u;
			ll bst=INF;
			for (int i=16; ~i; --i)
				if (anc[v][i]^-1&&d[anc[v][i]]>=d[b]) {
					bst=min(bst, lft[v][i]);
					v=anc[v][i];
				}
			assert(v==b);
			ll ans=min(dp[u], d[u]+min(bst, lft[b][0]));
			if (ans==INF)
				cout << "oo\n";
			else
				cout << ans << "\n";
		}
	}
	return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2764 KB Output is correct
2 Correct 4 ms 2816 KB Output is correct
3 Correct 4 ms 2764 KB Output is correct
4 Correct 4 ms 2840 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2764 KB Output is correct
2 Correct 4 ms 2816 KB Output is correct
3 Correct 4 ms 2764 KB Output is correct
4 Correct 4 ms 2840 KB Output is correct
5 Correct 3 ms 3020 KB Output is correct
6 Correct 3 ms 3020 KB Output is correct
7 Correct 2 ms 3020 KB Output is correct
8 Correct 2 ms 3020 KB Output is correct
9 Correct 2 ms 3020 KB Output is correct
10 Correct 2 ms 3020 KB Output is correct
11 Correct 3 ms 3020 KB Output is correct
12 Correct 3 ms 3020 KB Output is correct
13 Correct 3 ms 3020 KB Output is correct
14 Correct 2 ms 2952 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 158 ms 34536 KB Output is correct
2 Correct 159 ms 34280 KB Output is correct
3 Correct 152 ms 34272 KB Output is correct
4 Correct 195 ms 37484 KB Output is correct
5 Correct 160 ms 37468 KB Output is correct
6 Correct 206 ms 41356 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2764 KB Output is correct
2 Correct 4 ms 2816 KB Output is correct
3 Correct 4 ms 2764 KB Output is correct
4 Correct 4 ms 2840 KB Output is correct
5 Correct 3 ms 3020 KB Output is correct
6 Correct 3 ms 3020 KB Output is correct
7 Correct 2 ms 3020 KB Output is correct
8 Correct 2 ms 3020 KB Output is correct
9 Correct 2 ms 3020 KB Output is correct
10 Correct 2 ms 3020 KB Output is correct
11 Correct 3 ms 3020 KB Output is correct
12 Correct 3 ms 3020 KB Output is correct
13 Correct 3 ms 3020 KB Output is correct
14 Correct 2 ms 2952 KB Output is correct
15 Correct 158 ms 34536 KB Output is correct
16 Correct 159 ms 34280 KB Output is correct
17 Correct 152 ms 34272 KB Output is correct
18 Correct 195 ms 37484 KB Output is correct
19 Correct 160 ms 37468 KB Output is correct
20 Correct 206 ms 41356 KB Output is correct
21 Correct 147 ms 33992 KB Output is correct
22 Correct 139 ms 33684 KB Output is correct
23 Correct 176 ms 33604 KB Output is correct
24 Correct 174 ms 37332 KB Output is correct
25 Correct 179 ms 42160 KB Output is correct
26 Correct 133 ms 34036 KB Output is correct
27 Correct 164 ms 33724 KB Output is correct
28 Correct 148 ms 33716 KB Output is correct
29 Correct 212 ms 36184 KB Output is correct
30 Correct 186 ms 38644 KB Output is correct
31 Correct 154 ms 34196 KB Output is correct
32 Correct 140 ms 33860 KB Output is correct
33 Correct 179 ms 34048 KB Output is correct
34 Correct 180 ms 37096 KB Output is correct
35 Correct 189 ms 42036 KB Output is correct
36 Correct 160 ms 37312 KB Output is correct