oj.uz

답안 #896137

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
896137 2023-12-31T21:41:25 Z box Valley (BOI19_valley) C++17
100 / 100
 153 ms 44884 KB 
#include <bits/stdc++.h>
using namespace std;

#define ar array
#define all(v) begin(v), end(v)
#define sz(v) int(std::size(v))
using i64 = long long;
using pii = pair<int, int>;
using vi = vector<int>;

const i64 INF = 1e18;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N, S, Q, E;
    cin >> N >> S >> Q >> E, E--;
    vector<vector<pii>> adj(N);
    vector<pii> edges(N - 1);
    for (auto &[i, j] : edges) {
        int w; cin >> i >> j >> w, i--, j--;
        adj[i].push_back({j, w}), adj[j].push_back({i, w});
    }
    vi is_shop(N);
    while (S--) {
        int i; cin >> i, i--;
        is_shop[i] = 1;
    }
    const int LOG = 17;
    vector<ar<int, LOG>> parent(N);
    vector<ar<i64, LOG>> min_v(N);
    vi tin(N), tout(N), depth(N);
    vector<i64> dist_root(N);
    int timer = 0;
    vector<i64> dist(N);
    auto dfs = [&](auto dfs, int p, int i) -> void {
        dist[i] = is_shop[i] ? 0 : INF;
        tin[i] = timer++;
        parent[i][0] = p;
        for (int l = 1; l < LOG; l++) parent[i][l] = parent[parent[i][l - 1]][l - 1];
        for (auto [j, w] : adj[i]) if (p != j) {
            depth[j] = depth[i] + 1;
            dist_root[j] = dist_root[i] + w;
            dfs(dfs, i, j);
            dist[i] = min(dist[i], dist[j] + w);
        }
        tout[i] = timer - 1;
    };
    dfs(dfs, E, E);
    auto make_v = [&](auto make_v, int i) -> void {
        min_v[i][0] = dist[i] - dist_root[i];
        for (int l = 1; l < LOG; l++) min_v[i][l] = min(min_v[i][l - 1], min_v[parent[i][l - 1]][l - 1]);
        for (auto [j, w] : adj[i]) if (parent[i][0] != j) make_v(make_v, j);
    };
    make_v(make_v, E);
    vi lower(N - 1);
    for (int i = 0; i < sz(edges); i++)
        lower[i] = tin[edges[i].first] < tin[edges[i].second] ? edges[i].second : edges[i].first;
    auto is_anc = [&](int i, int j) {
        return tin[i] <= tin[j] && tout[i] >= tout[j];
    };
    while (Q--) {
        int h, i; cin >> h >> i, h--, i--;
        int j = lower[h];
        if (!is_anc(j, i)) {
            cout << "escaped\n";
            continue;
        }
        int d = depth[i] - depth[j] + 1, v = i;
        i64 best = INF;
        for (int l = 0; l < LOG; l++) if (d >> l & 1) {
            best = min(best, min_v[v][l]);
            v = parent[v][l];
        }
        best += dist_root[i];
        if (best > INF / 2) {
            cout << "oo\n";
            continue;
        }
        cout << best << '\n';
    }
}

Subtask #1
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 600 KB Output is correct
2 Correct 2 ms 768 KB Output is correct
3 Correct 2 ms 568 KB Output is correct
4 Correct 2 ms 604 KB Output is correct

Subtask #2
27.0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 600 KB Output is correct
2 Correct 2 ms 768 KB Output is correct
3 Correct 2 ms 568 KB Output is correct
4 Correct 2 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 672 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 1 ms 604 KB Output is correct
12 Correct 1 ms 604 KB Output is correct
13 Correct 1 ms 808 KB Output is correct
14 Correct 1 ms 604 KB Output is correct

Subtask #3
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 129 ms 35488 KB Output is correct
2 Correct 115 ms 35152 KB Output is correct
3 Correct 114 ms 35380 KB Output is correct
4 Correct 143 ms 39136 KB Output is correct
5 Correct 121 ms 38996 KB Output is correct
6 Correct 149 ms 43716 KB Output is correct

Subtask #4
41.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 600 KB Output is correct
2 Correct 2 ms 768 KB Output is correct
3 Correct 2 ms 568 KB Output is correct
4 Correct 2 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 672 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 1 ms 604 KB Output is correct
12 Correct 1 ms 604 KB Output is correct
13 Correct 1 ms 808 KB Output is correct
14 Correct 1 ms 604 KB Output is correct
15 Correct 129 ms 35488 KB Output is correct
16 Correct 115 ms 35152 KB Output is correct
17 Correct 114 ms 35380 KB Output is correct
18 Correct 143 ms 39136 KB Output is correct
19 Correct 121 ms 38996 KB Output is correct
20 Correct 149 ms 43716 KB Output is correct
21 Correct 105 ms 34812 KB Output is correct
22 Correct 111 ms 34624 KB Output is correct
23 Correct 116 ms 34388 KB Output is correct
24 Correct 150 ms 39036 KB Output is correct
25 Correct 143 ms 44884 KB Output is correct
26 Correct 107 ms 34748 KB Output is correct
27 Correct 118 ms 34640 KB Output is correct
28 Correct 108 ms 34476 KB Output is correct
29 Correct 123 ms 37460 KB Output is correct
30 Correct 153 ms 40572 KB Output is correct
31 Correct 121 ms 34984 KB Output is correct
32 Correct 108 ms 34568 KB Output is correct
33 Correct 113 ms 34640 KB Output is correct
34 Correct 138 ms 38736 KB Output is correct
35 Correct 134 ms 44624 KB Output is correct
36 Correct 117 ms 38996 KB Output is correct