oj.uz

Submission #633152

# Submission time Handle Problem Language Result Execution time Memory
633152 2022-08-21T17:19:21 Z a_aguilo Valley (BOI19_valley) C++14
59 / 100
 3000 ms 31040 KB 
#include<bits/stdc++.h>

using namespace std;

typedef vector<int> vi;
typedef vector<vi> vvi;

vi isShop, padre, level;
vector<pair<int, int>> edges;
vvi listaAdy, weights, dp;
int N, Q, E, S, LG;

void dfs(int nodo){
    for (int e = 0; e < listaAdy[nodo].size(); ++e){
        int vecino = listaAdy[nodo][e];
        int dist = weights[nodo][e];
        if(padre[nodo] == vecino) continue;
        padre[vecino] = nodo;
        level[vecino] = level[nodo]+1;
        dfs(vecino);
    }
}

int KthAncestor(int nodo, int K){
    for(int i = LG-1; i >= 0; --i){
        if((1 << i)<= K){
            K^=(1 << i);
            nodo = dp[nodo][i];
        }
    }
    return nodo;
}

void preprocess(){
    dfs(E);
    dp = vvi(N, vi(LG));
    for(int i = 0; i < N; ++i){
        dp[i][0] = padre[i];
    }
    for(int h = 1; h < LG; ++h){
        for(int nodo = 0; nodo < N; ++nodo){
            dp[nodo][h] = dp[dp[nodo][h-1]][h-1];
        }
    }
}

int getSon (pair<int, int> p){
    int a = p.first;
    int b = p.second;
    if (a == padre[b]) return b;
    return a;
}

long long dijkstra(int origin, pair<int, int> take){
    queue<pair<long long int, pair<int, int>>> PQ;
    long long int ans = 1e18;
    int u = take.first; int v = take.second;
    PQ.push({0, {origin, -1}});
    while(!PQ.empty()){
        pair<long long int, pair<int, int>> act;
        act = PQ.front(); PQ.pop();
        long long int dist = act.first;
        int nodo = act.second.first;
        int padre = act.second.second;
        if(isShop[nodo]){
            ans = min(ans, dist);
            continue;
        }
        for(int e = 0; e < listaAdy[nodo].size(); ++e){
            int vecino = listaAdy[nodo][e];
            int w = weights[nodo][e];
            if((vecino == u and nodo == v) or (vecino == v and nodo == u)) continue;
            if(vecino == padre) continue;
            PQ.push({(dist+(long long)w), {vecino, nodo}});
        }
    }
    return ans;
}

int main(){
    cin >> N >> S >> Q >> E; E--;
    int a, b, w, I, R;
    LG = log2(N) + 2;
    listaAdy = vvi(N);
    weights = vvi(N);
    level = vi(N);
    padre = vi(N);
    padre[E] = E;
    level[E] = 0;
    isShop = vi(N, 0);
    for(int i = 1; i < N; ++i){
        cin >> a >> b >> w;
        a--; b--;
        edges.push_back({a, b});
        listaAdy[a].push_back(b);
        listaAdy[b].push_back(a);
        weights[a].push_back(w);
        weights[b].push_back(w);
    }
    for(int i = 0; i < S; ++i){
        cin >> a; a--;
        isShop[a] = 1;
    }
    preprocess();
    while(Q--){
        cin >> I >> R; I--; R--;
        int son = getSon(edges[I]);
        int d = level[R] - level[son];
        if(KthAncestor(R, d) != son){
            cout << "escaped" << endl;
            continue;
        }
        long long ans = dijkstra(R, edges[I]);
        if(ans == 1e18) cout << "oo" << endl;
        else cout << ans << endl;
    }
    return 0;
}

Compilation message

valley.cpp: In function 'void dfs(int)':
valley.cpp:14:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |     for (int e = 0; e < listaAdy[nodo].size(); ++e){
      |                     ~~^~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:16:13: warning: unused variable 'dist' [-Wunused-variable]
   16 |         int dist = weights[nodo][e];
      |             ^~~~
valley.cpp: In function 'long long int dijkstra(int, std::pair<int, int>)':
valley.cpp:69:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |         for(int e = 0; e < listaAdy[nodo].size(); ++e){
      |                        ~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 440 KB Output is correct
2 Correct 17 ms 440 KB Output is correct
3 Correct 16 ms 424 KB Output is correct
4 Correct 16 ms 400 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 440 KB Output is correct
2 Correct 17 ms 440 KB Output is correct
3 Correct 16 ms 424 KB Output is correct
4 Correct 16 ms 400 KB Output is correct
5 Correct 4 ms 440 KB Output is correct
6 Correct 3 ms 468 KB Output is correct
7 Correct 3 ms 468 KB Output is correct
8 Correct 4 ms 436 KB Output is correct
9 Correct 6 ms 468 KB Output is correct
10 Correct 4 ms 468 KB Output is correct
11 Correct 3 ms 444 KB Output is correct
12 Correct 3 ms 452 KB Output is correct
13 Correct 4 ms 436 KB Output is correct
14 Correct 7 ms 468 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 389 ms 28496 KB Output is correct
2 Correct 403 ms 28080 KB Output is correct
3 Correct 410 ms 27704 KB Output is correct
4 Correct 448 ms 29300 KB Output is correct
5 Correct 425 ms 29376 KB Output is correct
6 Correct 518 ms 31040 KB Output is correct

Subtask #4
0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 440 KB Output is correct
2 Correct 17 ms 440 KB Output is correct
3 Correct 16 ms 424 KB Output is correct
4 Correct 16 ms 400 KB Output is correct
5 Correct 4 ms 440 KB Output is correct
6 Correct 3 ms 468 KB Output is correct
7 Correct 3 ms 468 KB Output is correct
8 Correct 4 ms 436 KB Output is correct
9 Correct 6 ms 468 KB Output is correct
10 Correct 4 ms 468 KB Output is correct
11 Correct 3 ms 444 KB Output is correct
12 Correct 3 ms 452 KB Output is correct
13 Correct 4 ms 436 KB Output is correct
14 Correct 7 ms 468 KB Output is correct
15 Correct 389 ms 28496 KB Output is correct
16 Correct 403 ms 28080 KB Output is correct
17 Correct 410 ms 27704 KB Output is correct
18 Correct 448 ms 29300 KB Output is correct
19 Correct 425 ms 29376 KB Output is correct
20 Correct 518 ms 31040 KB Output is correct
21 Correct 392 ms 28680 KB Output is correct
22 Correct 466 ms 27720 KB Output is correct
23 Correct 1310 ms 27376 KB Output is correct
24 Execution timed out 3075 ms 27568 KB Time limit exceeded
25 Halted 0 ms 0 KB -