oj.uz

Submission #540785

# Submission time Handle Problem Language Result Execution time Memory
540785 2022-03-21T17:31:52 Z Olympia Valley (BOI19_valley) C++17
100 / 100
 663 ms 93320 KB 
#include <vector>
#include <algorithm>
#include <iostream>
#include <set>
#include <cmath>
#include <map>
#include <random>
#include <cassert>
#include <ctime>
#include <cstdlib>
#include <queue>
#include <limits.h>
using namespace std;
class Tree {
private:
    int root;
    vector<vector<pair<int64_t,int64_t>>> adj; //node, weight
    vector<int64_t> parent, depth, sub, pre, post;
    map<pair<int64_t,int64_t>,int64_t> weight;
    vector<bool> isVillage;
    vector<vector<int64_t>> jmp, dp;
public:
    Tree (int64_t N, int64_t root) {
        adj.resize(N), this->root = root, parent.resize(N), depth.resize(N), isVillage.assign(N, false), sub.resize(N), pre.resize(N), post.resize(N);
    }
    void add_edge (int64_t u, int64_t v, int64_t w) {
        adj[u].push_back({v, w}), adj[v].push_back({u, w}), weight[{u, v}] = weight[{v, u}] = w;
    }
    void update_village (int u) {
        isVillage[u] = true;
    }
    int64_t cntr = 0;
    void dfs (int64_t curNode, int64_t prevNode) {
        parent[curNode] = prevNode, sub[curNode] = -1, pre[curNode] = cntr++;
        if (curNode == root) {
            depth[curNode] = 0;
        } else {
            depth[curNode] = depth[prevNode] + weight[{curNode, prevNode}];
        }
        for (pair<int64_t,int64_t> p: adj[curNode]) {
            if (p.first != prevNode) {
                dfs(p.first, curNode);
                if (sub[p.first] != -1) {
                    sub[curNode] = chmin(sub[p.first] + weight[{curNode, p.first}], sub[curNode]);
                }
            }
        }
        if (isVillage[curNode]) {
            sub[curNode] = 0;
        }
        post[curNode] = cntr++;
    }
    bool isAncestor (int64_t a, int64_t b) {
        //is a an ancestor of b?
        return (pre[a] <= pre[b] && post[a] >= post[b]);
    }
    int64_t chmin (int64_t a, int64_t b) {
        if (a == -1) return b;
        if (b == -1) return a;
        return min(a, b);
    }
    int64_t query (int64_t a1, int64_t a2, int64_t b) {
        if (parent[a1] != a2) {
            swap(a1, a2);
        }
        if (!isAncestor(a1, b)) {
            return -1;
        }
        int64_t x = b;
        int64_t ans = -1;
        for (int i = 31; i >= 0; i--) {
            if (isAncestor(a1, jmp[x][i])) {
                if (dp[x][i] != -1) {
                    ans = chmin(ans, dp[x][i] + abs(depth[x] - depth[b]));
                }
                x = jmp[x][i];
            }
        }
        if (sub[a1] != -1) {
            ans = chmin(ans, sub[a1] + abs(depth[b] - depth[a1]));
        }
        if (ans == -1) {
            return LLONG_MAX;
        }
        return ans;
    }
    void read () {
        dfs(root, -1);
        jmp.resize(adj.size());
        dp.resize(adj.size());
        for (int i = 0; i < adj.size(); i++) {
            jmp[i].resize(32);
            dp[i].resize(32);
            jmp[i][0] = parent[i];
        }
        jmp[root][0] = root;
        for (int j = 1; j < 32; j++) {
            for (int i = 0; i < adj.size(); i++) {
                jmp[i][j] = jmp[jmp[i][j - 1]][j - 1];
            }
        }
        for (int j = 0; j < 32; j++) {
            for (int i = 0; i < adj.size(); i++) {
                if (j == 0) {
                    dp[i][j] = sub[i];
                    if (sub[jmp[i][0]] != -1) {
                        dp[i][j] = chmin(dp[i][j], sub[jmp[i][0]] + weight[{jmp[i][0], i}]);
                    }
                    dp[root][0] = sub[root];
                } else {
                    dp[i][j] = dp[i][j - 1];
                    if (dp[jmp[i][j - 1]][j - 1] != -1) {
                        dp[i][j] = chmin(dp[i][j], dp[jmp[i][j - 1]][j - 1] + abs(depth[jmp[i][j - 1]] - depth[i]));
                    }
                }
            }
        }
    }
};
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int N, S, Q, E;
    cin >> N >> S >> Q >> E;
    E--;
    Tree myTree(N, E);
    vector<pair<int64_t,int64_t>> edges;
    for (int i = 0; i < N - 1; i++) {
        int64_t u, v, w;
        cin >> u >> v >> w;
        u--, v--;
        edges.emplace_back(u, v), myTree.add_edge(u, v, w);
    }
    while (S--) {
        int64_t x; cin >> x; x--; myTree.update_village(x);
    }
    myTree.read();
    while (Q--) {
        int64_t u, v;
        cin >> u >> v;
        u--, v--;
        int64_t x = myTree.query(edges[u].first, edges[u].second, v);
        if (x == -1) {
            cout << "escaped\n";
        } else if (x == LLONG_MAX) {
            cout << "oo\n";
        } else {
            cout << x << '\n';
        }
    }
}

Compilation message

valley.cpp: In member function 'void Tree::read()':
valley.cpp:91:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<std::pair<long int, long int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   91 |         for (int i = 0; i < adj.size(); i++) {
      |                         ~~^~~~~~~~~~~~
valley.cpp:98:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<std::pair<long int, long int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |             for (int i = 0; i < adj.size(); i++) {
      |                             ~~^~~~~~~~~~~~
valley.cpp:103:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<std::pair<long int, long int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  103 |             for (int i = 0; i < adj.size(); i++) {
      |                             ~~^~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 468 KB Output is correct
2 Correct 2 ms 468 KB Output is correct
3 Correct 3 ms 468 KB Output is correct
4 Correct 2 ms 468 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 468 KB Output is correct
2 Correct 2 ms 468 KB Output is correct
3 Correct 3 ms 468 KB Output is correct
4 Correct 2 ms 468 KB Output is correct
5 Correct 2 ms 1108 KB Output is correct
6 Correct 2 ms 1108 KB Output is correct
7 Correct 3 ms 1236 KB Output is correct
8 Correct 2 ms 1108 KB Output is correct
9 Correct 2 ms 1108 KB Output is correct
10 Correct 3 ms 1108 KB Output is correct
11 Correct 3 ms 1108 KB Output is correct
12 Correct 3 ms 1108 KB Output is correct
13 Correct 2 ms 1108 KB Output is correct
14 Correct 2 ms 1108 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 506 ms 84384 KB Output is correct
2 Correct 539 ms 84144 KB Output is correct
3 Correct 553 ms 84412 KB Output is correct
4 Correct 595 ms 87868 KB Output is correct
5 Correct 579 ms 87772 KB Output is correct
6 Correct 663 ms 91776 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 468 KB Output is correct
2 Correct 2 ms 468 KB Output is correct
3 Correct 3 ms 468 KB Output is correct
4 Correct 2 ms 468 KB Output is correct
5 Correct 2 ms 1108 KB Output is correct
6 Correct 2 ms 1108 KB Output is correct
7 Correct 3 ms 1236 KB Output is correct
8 Correct 2 ms 1108 KB Output is correct
9 Correct 2 ms 1108 KB Output is correct
10 Correct 3 ms 1108 KB Output is correct
11 Correct 3 ms 1108 KB Output is correct
12 Correct 3 ms 1108 KB Output is correct
13 Correct 2 ms 1108 KB Output is correct
14 Correct 2 ms 1108 KB Output is correct
15 Correct 506 ms 84384 KB Output is correct
16 Correct 539 ms 84144 KB Output is correct
17 Correct 553 ms 84412 KB Output is correct
18 Correct 595 ms 87868 KB Output is correct
19 Correct 579 ms 87772 KB Output is correct
20 Correct 663 ms 91776 KB Output is correct
21 Correct 446 ms 84540 KB Output is correct
22 Correct 447 ms 84384 KB Output is correct
23 Correct 473 ms 84536 KB Output is correct
24 Correct 538 ms 88308 KB Output is correct
25 Correct 560 ms 93320 KB Output is correct
26 Correct 460 ms 84376 KB Output is correct
27 Correct 462 ms 84232 KB Output is correct
28 Correct 476 ms 84648 KB Output is correct
29 Correct 554 ms 87056 KB Output is correct
30 Correct 641 ms 89852 KB Output is correct
31 Correct 486 ms 84604 KB Output is correct
32 Correct 508 ms 84312 KB Output is correct
33 Correct 522 ms 84676 KB Output is correct
34 Correct 592 ms 88016 KB Output is correct
35 Correct 611 ms 93060 KB Output is correct
36 Correct 570 ms 88572 KB Output is correct