oj.uz

Submission #411567

# Submission time Handle Problem Language Result Execution time Memory
411567 2021-05-25T13:55:49 Z ak2006 Valley (BOI19_valley) C++14
100 / 100
 498 ms 72024 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vi = vector<int>;
using vvi = vector<vi>;
using vb = vector<bool>;
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define pb push_back
const ll inf = 1e15;
void setIO()
{
	fast;
}
int n = 1e5 + 5,s,q,root;
vi in(n),out(n),num(n);
vl magic(n,inf),dist(n);
vvl anc(n,vl(21)),dp(n,vl(21));
vvvl adj(n);
vb shop(n);
int t;
void dfs(int u,int p,ll wt)
{
	if (p != -1)dist[u] = dist[p] + wt,num[u] = num[p] + 1;
	in[u] = t++;
	if (shop[u])magic[u] = dist[u];

	for (auto x:adj[u]){
		int v = x[0];
		ll w = x[1];
		if (v == p)continue;
		dfs(v,u,w);
		magic[u] = min(magic[u],magic[v]);
	}
	
	out[u] = t++;
}
bool is_ancestor(int u,int v)
{
	return in[u] <= in[v] && out[u] >= out[v];
}
void dfs2(int u,int p)
{
	anc[u][0] = p;
	dp[u][0] = magic[u];
	for (int i = 1;i<=20;i++){
		anc[u][i] = anc[anc[u][i - 1]][i - 1];
		dp[u][i] = min(dp[u][i - 1],dp[anc[u][i - 1]][i - 1]);
	}
	for (auto x:adj[u]){
		int v = x[0];
		if (v == p)continue;
		dfs2(v,u);
	}
}
int main()
{
	setIO();	
	cin>>n>>s>>q>>root;
	vvi edges;
	for (int i = 1;i<n;i++){
		int u,v,w;
		cin>>u>>v>>w;
		adj[u].pb({v,w});
		adj[v].pb({u,w});
		edges.pb({u,v});
	}
	for (int i = 1;i<=s;i++){
		int x;
		cin>>x;
		shop[x] = 1;
	}
	dfs(root,-1,0);
	for (int i = 1;i<=n;i++)if (magic[i] < inf)magic[i] += -2 * dist[i];
	dfs2(root,root);
	while (q--){
		int pos,u;
		cin>>pos>>u;
		int child = edges[pos - 1][0],par = edges[pos - 1][1];
		if (in[child] < in[par])swap(child,par);
		if (!is_ancestor(child,u))cout<<"escaped"<<'\n';
		else {
			//now find min of magic[v] for all v on the path from u to child
			int distance = - num[child] + num[u] + 1;
			int node = u;
			ll val = inf;
			for (int i = 0;i<=20;i++){
				if (distance&(1<<i)){
					val = min(val,dp[u][i]);
					u = anc[u][i];
				}
			}
			if (val >= inf)cout<<"oo"<<'\n';
			else cout<<dist[node] + val<<'\n';
		}
	}
	return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 34 ms 44620 KB Output is correct
2 Correct 38 ms 44664 KB Output is correct
3 Correct 38 ms 44624 KB Output is correct
4 Correct 37 ms 44620 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 34 ms 44620 KB Output is correct
2 Correct 38 ms 44664 KB Output is correct
3 Correct 38 ms 44624 KB Output is correct
4 Correct 37 ms 44620 KB Output is correct
5 Correct 34 ms 44740 KB Output is correct
6 Correct 36 ms 44656 KB Output is correct
7 Correct 35 ms 44844 KB Output is correct
8 Correct 38 ms 44716 KB Output is correct
9 Correct 36 ms 44696 KB Output is correct
10 Correct 38 ms 44784 KB Output is correct
11 Correct 38 ms 44740 KB Output is correct
12 Correct 34 ms 44740 KB Output is correct
13 Correct 34 ms 44792 KB Output is correct
14 Correct 33 ms 44756 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 376 ms 63208 KB Output is correct
2 Correct 369 ms 63300 KB Output is correct
3 Correct 430 ms 63300 KB Output is correct
4 Correct 477 ms 66592 KB Output is correct
5 Correct 404 ms 66672 KB Output is correct
6 Correct 498 ms 70676 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 34 ms 44620 KB Output is correct
2 Correct 38 ms 44664 KB Output is correct
3 Correct 38 ms 44624 KB Output is correct
4 Correct 37 ms 44620 KB Output is correct
5 Correct 34 ms 44740 KB Output is correct
6 Correct 36 ms 44656 KB Output is correct
7 Correct 35 ms 44844 KB Output is correct
8 Correct 38 ms 44716 KB Output is correct
9 Correct 36 ms 44696 KB Output is correct
10 Correct 38 ms 44784 KB Output is correct
11 Correct 38 ms 44740 KB Output is correct
12 Correct 34 ms 44740 KB Output is correct
13 Correct 34 ms 44792 KB Output is correct
14 Correct 33 ms 44756 KB Output is correct
15 Correct 376 ms 63208 KB Output is correct
16 Correct 369 ms 63300 KB Output is correct
17 Correct 430 ms 63300 KB Output is correct
18 Correct 477 ms 66592 KB Output is correct
19 Correct 404 ms 66672 KB Output is correct
20 Correct 498 ms 70676 KB Output is correct
21 Correct 343 ms 63336 KB Output is correct
22 Correct 342 ms 63380 KB Output is correct
23 Correct 354 ms 63472 KB Output is correct
24 Correct 425 ms 67144 KB Output is correct
25 Correct 481 ms 72024 KB Output is correct
26 Correct 325 ms 63284 KB Output is correct
27 Correct 347 ms 63304 KB Output is correct
28 Correct 358 ms 63480 KB Output is correct
29 Correct 419 ms 65916 KB Output is correct
30 Correct 488 ms 68448 KB Output is correct
31 Correct 347 ms 63388 KB Output is correct
32 Correct 359 ms 63408 KB Output is correct
33 Correct 362 ms 63560 KB Output is correct
34 Correct 441 ms 66796 KB Output is correct
35 Correct 475 ms 71904 KB Output is correct
36 Correct 419 ms 67524 KB Output is correct