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Submission #879975

# Submission time Handle Problem Language Result Execution time Memory
879975 2023-11-28T12:35:19 Z VectorLi Valley (BOI19_valley) C++17
100 / 100
 106 ms 40520 KB 
#include <bits/stdc++.h>
#define long long long

using namespace std;

const int V = (int) 1E5, K = 17;
const long MAX = numeric_limits<long>::max();

struct Element {
    long a;
};

const Element E = {MAX};

Element operator + (Element u, Element v) {
    Element w;
    w.a = min(u.a, v.a);
    return w;
}

int n, m, q, s;
vector<pair<int, long>> e1[V];
pair<int, int> e2[V - 1];
bool t[V];
int p[K][V], d1[V], h[V], l[V], c;
long d2[V], f[V];
Element g[K][V];

void DFS(int u) {
    h[u] = 1;
    l[u] = c;
    c = c + 1;
    f[u] = t[u] ? d2[u] : MAX;
    for (auto [v, w] : e1[u]) {
        if (v != p[0][u]) {
            p[0][v] = u;
            d1[v] = d1[u] + 1;
            d2[v] = d2[u] + w;
            DFS(v);
            h[u] = h[u] + h[v];
            f[u] = min(f[u], f[v]);
        }
    }
}

Element query(int u, int v) {
    Element x = E;
    if (d1[u] > d1[v]) {
        swap(u, v);
    }
    for (int i = K - 1; i >= 0; i--) {
        if ((d1[v] - d1[u]) >> i & 1) {
            x = x + g[i][v];
            v = p[i][v];
        }
    }
    if (u == v) {
        return x + g[0][u];
    }
    assert(false);
}

int lower(int i) {
    int u, v;
    tie(u, v) = e2[i];
    return d1[u] > d1[v] ? u : v;
}

void solve() {
    cin >> n >> m >> q >> s;
    s = s - 1;
    for (int i = 0; i < n - 1; i++) {
        int u, v;
        long w;
        cin >> u >> v >> w;
        u = u - 1, v = v - 1;
        e1[u].push_back({v, w});
        e1[v].push_back({u, w});
        e2[i] = {u, v};
    }
    for (int i = 0; i < m; i++) {
        int u;
        cin >> u;
        u = u - 1;
        t[u] = true;
    }

    p[0][s] = -1;
    DFS(s);
    for (int u = 0; u < n; u++) {
        if (f[u] < MAX) {
            f[u] = f[u] - d2[u] * 2;
        }
        g[0][u] = {f[u]};
    }

    for (int i = 0; i < K - 1; i++) {
        for (int u = 0; u < n; u++) {
            if (p[i][u] < 0) {
                p[i + 1][u] = -1;
                g[i + 1][u] = g[i][u];
            } else {
                p[i + 1][u] = p[i][p[i][u]];
                g[i + 1][u] = g[i][u] + g[i][p[i][u]];
            }
        }
    }

    for (int i = 0; i < q; i++) {
        int j;
        cin >> j;
        j = j - 1;
        int u, v;
        cin >> u;
        u = u - 1;
        v = lower(j);
        if (not (l[v] <= l[u] && l[v] + h[v] > l[u])) {
            cout << "escaped" << "\n";
        } else {
            Element x = query(u, v);
            if (x.a < MAX) {
                cout << d2[u] + x.a << "\n";
            } else {
                cout << "oo" << "\n";
            }
        }
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 26204 KB Output is correct
2 Correct 5 ms 26204 KB Output is correct
3 Correct 6 ms 26204 KB Output is correct
4 Correct 5 ms 24156 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 26204 KB Output is correct
2 Correct 5 ms 26204 KB Output is correct
3 Correct 6 ms 26204 KB Output is correct
4 Correct 5 ms 24156 KB Output is correct
5 Correct 4 ms 26204 KB Output is correct
6 Correct 5 ms 26200 KB Output is correct
7 Correct 4 ms 26204 KB Output is correct
8 Correct 5 ms 26204 KB Output is correct
9 Correct 4 ms 24156 KB Output is correct
10 Correct 4 ms 26256 KB Output is correct
11 Correct 4 ms 24156 KB Output is correct
12 Correct 5 ms 24256 KB Output is correct
13 Correct 4 ms 24156 KB Output is correct
14 Correct 4 ms 26200 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 35824 KB Output is correct
2 Correct 102 ms 35624 KB Output is correct
3 Correct 85 ms 35928 KB Output is correct
4 Correct 93 ms 37944 KB Output is correct
5 Correct 80 ms 37972 KB Output is correct
6 Correct 106 ms 40244 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 26204 KB Output is correct
2 Correct 5 ms 26204 KB Output is correct
3 Correct 6 ms 26204 KB Output is correct
4 Correct 5 ms 24156 KB Output is correct
5 Correct 4 ms 26204 KB Output is correct
6 Correct 5 ms 26200 KB Output is correct
7 Correct 4 ms 26204 KB Output is correct
8 Correct 5 ms 26204 KB Output is correct
9 Correct 4 ms 24156 KB Output is correct
10 Correct 4 ms 26256 KB Output is correct
11 Correct 4 ms 24156 KB Output is correct
12 Correct 5 ms 24256 KB Output is correct
13 Correct 4 ms 24156 KB Output is correct
14 Correct 4 ms 26200 KB Output is correct
15 Correct 72 ms 35824 KB Output is correct
16 Correct 102 ms 35624 KB Output is correct
17 Correct 85 ms 35928 KB Output is correct
18 Correct 93 ms 37944 KB Output is correct
19 Correct 80 ms 37972 KB Output is correct
20 Correct 106 ms 40244 KB Output is correct
21 Correct 68 ms 35304 KB Output is correct
22 Correct 68 ms 35152 KB Output is correct
23 Correct 81 ms 35300 KB Output is correct
24 Correct 98 ms 37428 KB Output is correct
25 Correct 86 ms 40388 KB Output is correct
26 Correct 64 ms 35492 KB Output is correct
27 Correct 74 ms 35156 KB Output is correct
28 Correct 74 ms 35540 KB Output is correct
29 Correct 81 ms 36944 KB Output is correct
30 Correct 88 ms 38460 KB Output is correct
31 Correct 68 ms 35408 KB Output is correct
32 Correct 69 ms 35228 KB Output is correct
33 Correct 77 ms 35664 KB Output is correct
34 Correct 89 ms 37428 KB Output is correct
35 Correct 88 ms 40520 KB Output is correct
36 Correct 81 ms 37480 KB Output is correct