oj.uz

Submission #960920

# Submission time Handle Problem Language Result Execution time Memory
960920 2024-04-11T08:46:22 Z Ghetto Chase (CEOI17_chase) C++17
40 / 100
 4000 ms 42248 KB 
#include <bits/stdc++.h>
#pragma GCC optimize("03", "unroll-loops")
#pragma GCC target("avx2", "bmi", "bmi2", "lzcnt", "popcnt")
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.sync_with_stdio(false);
    cin.tie(0);

    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();

    assert(topo_order.size() <= 3e5);
    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:23:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     for (int i = 1; i < adj[u].size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~
chase.cpp: In function 'int main()':
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++)
      |                             ~~^~~~~~~~~~~~~~~
chase.cpp:83:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   83 |             for (int i = 1; i < adj[u].size(); i++)
      |                             ~~^~~~~~~~~~~~~~~
chase.cpp:85:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   85 |             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 12888 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 12888 KB Output is correct
5 Correct 3 ms 12892 KB Output is correct
6 Correct 3 ms 12888 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12888 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 12888 KB Output is correct
5 Correct 3 ms 12892 KB Output is correct
6 Correct 3 ms 12888 KB Output is correct
7 Correct 11 ms 13148 KB Output is correct
8 Correct 4 ms 13216 KB Output is correct
9 Correct 25 ms 13212 KB Output is correct
10 Correct 9 ms 13148 KB Output is correct
11 Correct 6 ms 13204 KB Output is correct
12 Correct 4 ms 12960 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3726 ms 41920 KB Output is correct
2 Correct 3917 ms 42248 KB Output is correct
3 Execution timed out 4035 ms 26992 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 12888 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 12888 KB Output is correct
5 Correct 3 ms 12892 KB Output is correct
6 Correct 3 ms 12888 KB Output is correct
7 Correct 11 ms 13148 KB Output is correct
8 Correct 4 ms 13216 KB Output is correct
9 Correct 25 ms 13212 KB Output is correct
10 Correct 9 ms 13148 KB Output is correct
11 Correct 6 ms 13204 KB Output is correct
12 Correct 4 ms 12960 KB Output is correct
13 Correct 3726 ms 41920 KB Output is correct
14 Correct 3917 ms 42248 KB Output is correct
15 Execution timed out 4035 ms 26992 KB Time limit exceeded
16 Halted 0 ms 0 KB -