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답안 #911085

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
911085 2024-01-18T12:38:10 Z VMaksimoski008 Valley (BOI19_valley) C++14
100 / 100
 386 ms 38688 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;

const int LOG = 20, maxn = 1e5 + 5;
 
int n, s, q, e, timer = 0;
vector<vector<pii> > graph;
int store[maxn+1], in[maxn+1], out[maxn+1], depth[maxn+1], up[maxn+1][LOG];
ll dp[maxn+1], dist[maxn+1], mn[maxn+1][LOG];
 
void dfs(int u, int p) {
    in[u] = timer++;
    dp[u] = (store[u] ? dist[u] : 1e17);
 
    for(auto &[v, w] : graph[u]) {
        if(v == p) continue;
        dist[v] = dist[u] + w;
        dfs(v, u);
        dp[u] = min(dp[u], dp[v]);
    }
 
    out[u] = timer;
}

void dfs2(int u, int p) {
    for(int i=1; i<LOG; i++) {
        up[u][i] = up[ up[u][i-1] ][i-1];
        mn[u][i] = min(mn[u][i-1], mn[ up[u][i-1] ][i-1]);
    }

    for(auto &[v, _] : graph[u]) {
        if(v == p) continue;
        up[v][0] = u;
        mn[v][0] = dp[u];
        dfs2(v, u);
    }
}
 
bool anc(int u, int v) { return (in[u] <= in[v] && out[u] >= out[v]); }
 
int32_t main() {
    cin >> n >> s >> q >> e;
    vector<pii> edges;
    graph.resize(n+1);
 
    for(int i=0; i<n-1; i++) {
        int a, b, w;
        cin >> a >> b >> w;
        edges.push_back({ a, b });
        graph[a].push_back({ b, w });
        graph[b].push_back({ a, w });
    }
 
    for(int i=0; i<s; i++) {
        int x;
        cin >> x;
        store[x] = 1;
    }
 
    dfs(e, 0);
    for(int u=1; u<=n; u++) dp[u] -= 2 * dist[u];
    dfs2(e, 0);
 
    while(q--) {
        int I, R;
        cin >> I >> R;
        pii edge = edges[I-1];
 
        if(in[edge.first] < in[edge.second]) swap(edge.first, edge.second);
        if(anc(edge.first, R) == anc(edge.first, e)) {
            cout << "escaped\n";
            continue;
        }

        ll ans = dp[R] + dist[R];
        int u = R;
        
        for(int j=LOG-1; j>=0; j--) {
            if(up[u][j] == 0) continue;
            if(!anc(edge.first, up[u][j])) continue;
            ans = min(ans, dist[R] + mn[u][j]);
            u = up[u][j];
        }

        if(ans >= 1e15) cout << "oo\n";
        else cout << ans << '\n';
    }

    return 0;
}

Compilation message

valley.cpp: In function 'void dfs(int, int)':
valley.cpp:17:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   17 |     for(auto &[v, w] : graph[u]) {
      |               ^
valley.cpp: In function 'void dfs2(int, int)':
valley.cpp:33:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   33 |     for(auto &[v, _] : graph[u]) {
      |               ^

Subtask #1
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 15 ms 2392 KB Output is correct
2 Correct 16 ms 2396 KB Output is correct
3 Correct 15 ms 2392 KB Output is correct
4 Correct 15 ms 344 KB Output is correct

Subtask #2
27.0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 15 ms 2392 KB Output is correct
2 Correct 16 ms 2396 KB Output is correct
3 Correct 15 ms 2392 KB Output is correct
4 Correct 15 ms 344 KB Output is correct
5 Correct 3 ms 2652 KB Output is correct
6 Correct 4 ms 2840 KB Output is correct
7 Correct 4 ms 2652 KB Output is correct
8 Correct 3 ms 2648 KB Output is correct
9 Correct 3 ms 604 KB Output is correct
10 Correct 3 ms 2652 KB Output is correct
11 Correct 3 ms 604 KB Output is correct
12 Correct 3 ms 600 KB Output is correct
13 Correct 3 ms 604 KB Output is correct
14 Correct 3 ms 2652 KB Output is correct

Subtask #3
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 337 ms 34244 KB Output is correct
2 Correct 343 ms 33892 KB Output is correct
3 Correct 352 ms 33732 KB Output is correct
4 Correct 377 ms 35696 KB Output is correct
5 Correct 328 ms 35756 KB Output is correct
6 Correct 385 ms 37560 KB Output is correct

Subtask #4
41.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 15 ms 2392 KB Output is correct
2 Correct 16 ms 2396 KB Output is correct
3 Correct 15 ms 2392 KB Output is correct
4 Correct 15 ms 344 KB Output is correct
5 Correct 3 ms 2652 KB Output is correct
6 Correct 4 ms 2840 KB Output is correct
7 Correct 4 ms 2652 KB Output is correct
8 Correct 3 ms 2648 KB Output is correct
9 Correct 3 ms 604 KB Output is correct
10 Correct 3 ms 2652 KB Output is correct
11 Correct 3 ms 604 KB Output is correct
12 Correct 3 ms 600 KB Output is correct
13 Correct 3 ms 604 KB Output is correct
14 Correct 3 ms 2652 KB Output is correct
15 Correct 337 ms 34244 KB Output is correct
16 Correct 343 ms 33892 KB Output is correct
17 Correct 352 ms 33732 KB Output is correct
18 Correct 377 ms 35696 KB Output is correct
19 Correct 328 ms 35756 KB Output is correct
20 Correct 385 ms 37560 KB Output is correct
21 Correct 315 ms 34060 KB Output is correct
22 Correct 338 ms 33628 KB Output is correct
23 Correct 316 ms 33400 KB Output is correct
24 Correct 386 ms 35444 KB Output is correct
25 Correct 344 ms 38372 KB Output is correct
26 Correct 302 ms 34244 KB Output is correct
27 Correct 331 ms 33776 KB Output is correct
28 Correct 327 ms 33856 KB Output is correct
29 Correct 327 ms 35264 KB Output is correct
30 Correct 344 ms 36524 KB Output is correct
31 Correct 301 ms 34248 KB Output is correct
32 Correct 338 ms 34000 KB Output is correct
33 Correct 335 ms 33988 KB Output is correct
34 Correct 354 ms 36108 KB Output is correct
35 Correct 340 ms 38688 KB Output is correct
36 Correct 352 ms 36620 KB Output is correct