oj.uz

Submission #960906

# Submission time Handle Problem Language Result Execution time Memory
960906 2024-04-11T08:04:11 Z Ghetto Chase (CEOI17_chase) C++17
40 / 100
 4000 ms 43580 KB 
#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
using lint = long long;
const int MAX_N = 1e5 + 5, MAX_K = 1e2 + 5;

int n, k;
lint val[MAX_N];
vector<int> adj[MAX_N], adj_ind[MAX_N]; // adj_ind[u][i] = ind of adj list u is for adj[u][i]
void init() {
    for (int i = 1; i <= n; i++) {
        adj[i].push_back(0);
        adj_ind[i].push_back(0);
    }
}

vector<int> seen[MAX_N];
vector<pii> topo_order;
void dfs(int u, int prev) {
    seen[u][prev] = 1;
    for (int i = 1; i < adj[u].size(); i++) {
        if (i == prev) continue;
        int v = adj[u][i];
        if (seen[v][adj_ind[u][i]] == 1) assert(true == false);
        if (!seen[v][adj_ind[u][i]]) dfs(v, adj_ind[u][i]);
    }
    seen[u][prev] = 2;
    topo_order.push_back({u, prev});
}

vector<lint> dp[MAX_N][2];
void precomp() {
    for (int i = 1; i <= n; i++)
        seen[i].resize(adj[i].size() + 2);
    
    for (int i = 1; i <= n; i++)
        dfs(i, 0);
    reverse(topo_order.begin(), topo_order.end());

    for (int i = 1; i <= n; i++) {
        for (int c = 0; c <= 1; c++) {
            dp[i][c].resize(adj[i].size() + 2);
        }
    }
}

int main() {
    // freopen("chase.in", "r", stdin);

    cin >> n >> k;
    init();

    for (int i = 1; i <= n; i++) cin >> val[i];
    for (int i = 1; i < n; i++) {
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);

        int u_ind = adj[u].size() - 1, v_ind = adj[v].size() - 1;
        adj_ind[u].push_back(v_ind);
        adj_ind[v].push_back(u_ind);
    }

    precomp();

    for (int c = 1; c <= k; c++) {
        int p = c % 2, opp_p = (c + 1) % 2;

        for (int j = topo_order.size() - 1; j >= 0; j--) {
            int u = topo_order[j].first, prev = topo_order[j].second;

            lint leave = 0;
            for (int i = 1; i < adj[u].size(); i++)
                if (i != prev) leave = max(leave, dp[adj[u][i]][p][adj_ind[u][i]]);

            lint take = 0;
            for (int i = 1; i < adj[u].size(); i++)
                if (i != prev) take = max(take, dp[adj[u][i]][opp_p][adj_ind[u][i]]);
            for (int i = 1; i < adj[u].size(); i++)
                if (i != prev) take += val[adj[u][i]];
            
            dp[u][p][prev] = max(take, leave);
        }
    }

    lint ans = 0;
    for (int i = 1; i <= n; i++) ans = max(ans, dp[i][k % 2][0]);
    cout << ans << '\n';
}

Compilation message

chase.cpp: In function 'void dfs(int, int)':
chase.cpp:21:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |     for (int i = 1; i < adj[u].size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~
chase.cpp: In function 'int main()':
chase.cpp:73:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |             for (int i = 1; i < adj[u].size(); i++)
      |                             ~~^~~~~~~~~~~~~~~
chase.cpp:77:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |             for (int i = 1; i < adj[u].size(); i++)
      |                             ~~^~~~~~~~~~~~~~~
chase.cpp:79:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |             for (int i = 1; i < adj[u].size(); i++)
      |                             ~~^~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12892 KB Output is correct
2 Correct 3 ms 12892 KB Output is correct
3 Correct 3 ms 12892 KB Output is correct
4 Correct 3 ms 12732 KB Output is correct
5 Correct 4 ms 12892 KB Output is correct
6 Correct 3 ms 12892 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12892 KB Output is correct
2 Correct 3 ms 12892 KB Output is correct
3 Correct 3 ms 12892 KB Output is correct
4 Correct 3 ms 12732 KB Output is correct
5 Correct 4 ms 12892 KB Output is correct
6 Correct 3 ms 12892 KB Output is correct
7 Correct 8 ms 13148 KB Output is correct
8 Correct 4 ms 13148 KB Output is correct
9 Correct 24 ms 13148 KB Output is correct
10 Correct 10 ms 13148 KB Output is correct
11 Correct 6 ms 13148 KB Output is correct
12 Correct 5 ms 12992 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3893 ms 43580 KB Output is correct
2 Correct 3740 ms 42844 KB Output is correct
3 Execution timed out 4035 ms 27696 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #4
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12892 KB Output is correct
2 Correct 3 ms 12892 KB Output is correct
3 Correct 3 ms 12892 KB Output is correct
4 Correct 3 ms 12732 KB Output is correct
5 Correct 4 ms 12892 KB Output is correct
6 Correct 3 ms 12892 KB Output is correct
7 Correct 8 ms 13148 KB Output is correct
8 Correct 4 ms 13148 KB Output is correct
9 Correct 24 ms 13148 KB Output is correct
10 Correct 10 ms 13148 KB Output is correct
11 Correct 6 ms 13148 KB Output is correct
12 Correct 5 ms 12992 KB Output is correct
13 Correct 3893 ms 43580 KB Output is correct
14 Correct 3740 ms 42844 KB Output is correct
15 Execution timed out 4035 ms 27696 KB Time limit exceeded
16 Halted 0 ms 0 KB -