oj.uz

Submission #586793

# Submission time Handle Problem Language Result Execution time Memory
586793 2022-06-30T17:11:32 Z blue Valley (BOI19_valley) C++17
100 / 100
 203 ms 36640 KB 
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

using vi = vector<int>;
using vvi = vector<vi>;
using ll = long long;
using vll = vector<ll>;
#define sz(x) int(x.size())

const int mx = 100'001;
const int lg = 17;
const ll inf = 1'000'000'000'000'000'000LL;

int N, S, Q, E;

vi A(1+mx), B(1+mx);
vll W(1+mx);
vi edgeind[1+mx];

vll nearshop(1+mx, inf); //distance to closest shop within subtree


vi parent(1+mx, 0);
vi paredge(1+mx, 0);
vll distE(1+mx, 0);
vi depth(1+mx, 0);

vi edgelower(1+mx, 0);

int dfsct = 0;
vi dfsind(1+mx, 0);
vi subtree(1+mx, 1);

void dfs(int u, int p)
{
	dfsct++;
	dfsind[u] = dfsct;

	for(int e : edgeind[u])
	{
		int v = A[e] + B[e] - u;
		ll w = W[e];

		if(v == p)
			continue;

		parent[v] = u;
		paredge[v] = e;
		edgelower[e] = v;

		distE[v] = distE[u] + w;
		depth[v] = depth[u] + 1;

		dfs(v, u);

		nearshop[u] = min(nearshop[u], nearshop[v] + w);

		subtree[u] += subtree[v];
	}
}

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	cin >> N >> S >> Q >> E;

	for(int e = 1; e <= N-1; e++)
	{
		cin >> A[e] >> B[e] >> W[e];
		edgeind[A[e]].push_back(e);
		edgeind[B[e]].push_back(e);
	}

	for(int x = 1; x <= S; x++)
	{
		int u;
		cin >> u;
		nearshop[u] = 0;
	}

	dfs(E, 0);

	parent[E] = E;

	ll lft[1+N][1+lg];
	int anc[1+N][1+lg];
	for(int i = 1; i <= N; i++)
	{
		lft[i][0] = nearshop[i] - distE[i];
		anc[i][0] = parent[i];
	}

	for(int e = 1; e <= lg; e++)
	{
		for(int i = 1; i <= N; i++)
		{
			anc[i][e] = anc[ anc[i][e-1] ][e-1];
			lft[i][e] = min(lft[i][e-1], lft[ anc[i][e-1] ][e-1]);
		}
	}

	// cerr << "nearshop = ";
	// for(int i = 1; i <= N; i++)
	// 	cerr << nearshop[i] << ' ';
	// cerr << '\n';


	for(int q = 1; q <= Q; q++)
	{
		int I, R;
		cin >> I >> R;

		bool escape;
		int A;

		if(R == E)
			escape = 1;
		else
		{
			A = edgelower[I];
			if(dfsind[A] <= dfsind[R] && dfsind[R] < dfsind[A] + subtree[A])
				escape = 0;
			else
				escape = 1;
		}

		if(escape)
			cout << "escaped\n";
		else
		{
			if(nearshop[A] >= inf)
				cout << "oo\n";
			else
			{
				// cerr << "A = " << A << '\n';
				ll res = inf;
				int u = R;
				for(int e = lg; e >= 0; e--)
				{
					if((1 << e) & (depth[u] - depth[A] + 1))
					{
						// cerr << "jump by " << (1<<e) << '\n';
						res = min(res, distE[R] + lft[u][e]);
						u = anc[u][e];
					}
				}

				cout << res << '\n';
			}
		}
	}
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8148 KB Output is correct
2 Correct 6 ms 8276 KB Output is correct
3 Correct 5 ms 8276 KB Output is correct
4 Correct 6 ms 8276 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8148 KB Output is correct
2 Correct 6 ms 8276 KB Output is correct
3 Correct 5 ms 8276 KB Output is correct
4 Correct 6 ms 8276 KB Output is correct
5 Correct 4 ms 8364 KB Output is correct
6 Correct 5 ms 8456 KB Output is correct
7 Correct 6 ms 8444 KB Output is correct
8 Correct 5 ms 8448 KB Output is correct
9 Correct 5 ms 8324 KB Output is correct
10 Correct 5 ms 8452 KB Output is correct
11 Correct 5 ms 8404 KB Output is correct
12 Correct 5 ms 8448 KB Output is correct
13 Correct 4 ms 8404 KB Output is correct
14 Correct 5 ms 8404 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 126 ms 33212 KB Output is correct
2 Correct 137 ms 32936 KB Output is correct
3 Correct 144 ms 32864 KB Output is correct
4 Correct 158 ms 32888 KB Output is correct
5 Correct 138 ms 33080 KB Output is correct
6 Correct 203 ms 32912 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8148 KB Output is correct
2 Correct 6 ms 8276 KB Output is correct
3 Correct 5 ms 8276 KB Output is correct
4 Correct 6 ms 8276 KB Output is correct
5 Correct 4 ms 8364 KB Output is correct
6 Correct 5 ms 8456 KB Output is correct
7 Correct 6 ms 8444 KB Output is correct
8 Correct 5 ms 8448 KB Output is correct
9 Correct 5 ms 8324 KB Output is correct
10 Correct 5 ms 8452 KB Output is correct
11 Correct 5 ms 8404 KB Output is correct
12 Correct 5 ms 8448 KB Output is correct
13 Correct 4 ms 8404 KB Output is correct
14 Correct 5 ms 8404 KB Output is correct
15 Correct 126 ms 33212 KB Output is correct
16 Correct 137 ms 32936 KB Output is correct
17 Correct 144 ms 32864 KB Output is correct
18 Correct 158 ms 32888 KB Output is correct
19 Correct 138 ms 33080 KB Output is correct
20 Correct 203 ms 32912 KB Output is correct
21 Correct 129 ms 36528 KB Output is correct
22 Correct 125 ms 36296 KB Output is correct
23 Correct 159 ms 36180 KB Output is correct
24 Correct 125 ms 36192 KB Output is correct
25 Correct 159 ms 36564 KB Output is correct
26 Correct 124 ms 36596 KB Output is correct
27 Correct 115 ms 36252 KB Output is correct
28 Correct 125 ms 36208 KB Output is correct
29 Correct 162 ms 36564 KB Output is correct
30 Correct 196 ms 36640 KB Output is correct
31 Correct 126 ms 36640 KB Output is correct
32 Correct 148 ms 36520 KB Output is correct
33 Correct 128 ms 36428 KB Output is correct
34 Correct 161 ms 36368 KB Output is correct
35 Correct 162 ms 36576 KB Output is correct
36 Correct 135 ms 36084 KB Output is correct