oj.uz

Submission #960961

# Submission time Handle Problem Language Result Execution time Memory
960961 2024-04-11T09:55:08 Z Ghetto Chase (CEOI17_chase) C++17
40 / 100
 4000 ms 118600 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]

int par[MAX_N];
vector<int> children[MAX_N];
void init1() {
    for (int i = 1; i <= n; i++) children[i].push_back(0);
}
int child_ind[MAX_N];

int n_inds, ind[MAX_N], rev_ind[MAX_N];
void dfs(int u) {
    ind[u] = ++n_inds;
    rev_ind[ind[u]] = u;
    for (int v : adj[u]) {
        if (ind[v]) continue;
        par[v] = u;
        children[u].push_back(v);
        child_ind[v] = children[u].size() - 1;
        dfs(v);
    }
}

lint val_sum[MAX_N];

void precomp() {
    init1();

    dfs(1);

    for (int i = 1; i <= n; i++)
        for (int j : adj[i]) val_sum[i] += val[j];
}

lint dp1[MAX_N][MAX_K];
vector<lint> dp2[MAX_N][2];
lint max_dp2[MAX_N][2];
void init2() {
    for (int i = 1; i <= n; i++)
        for (int c = 0; c <= 1; c++)
            dp2[i][c].resize(adj[i].size() + 2);
}

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

    cin >> n >> k;
    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);
    }

    precomp();

    for (int c = 1; c <= k; c++) {
        for (int i = n; i >= 1; i--) {
            int u = rev_ind[i];

            lint leave = 0;
            for (int v : children[u])
                if (v != 0) leave = max(leave, dp1[v][c]);

            lint take = 0; 
            for (int v : children[u])
                if (v != 0) take = max(take, dp1[v][c - 1]);
            take += val_sum[u] - val[par[u]];

            dp1[u][c] = max(take, leave);
        }
    }

    init2();
    lint ans = 0;
    for (int c = 0; c <= k; c++) {
        int opp_c = k - c;
        int p = c % 2, opp_p = (c + 1) % 2;
        for (int i = n; i >= 1; i--) {
            int u = rev_ind[i];

            multiset<lint> trans;
            trans.insert(0);
            for (int v : children[u]) trans.insert(dp1[v][opp_c]); // Should have 0

            max_dp2[u][p] = 0;
            for (int j = 0; j < children[u].size(); j++) {
                if (c == 0) continue;
                int v = children[u][j];

                lint leave = (v == 0) ? 0 : max_dp2[v][p];
                lint take = val_sum[u] - val[v] + ((v == 0) ? 0 : max_dp2[v][opp_p]);
                dp2[u][p][j] = max(take, leave);
                max_dp2[u][p] = max(max_dp2[u][p], dp2[u][p][j]);
            }
            
            for (int j = 0; j < children[u].size(); j++) {
                int v = children[u][j];
                trans.erase(trans.find(dp1[v][opp_c]));

                assert(trans.size());
                ans = max(ans, dp2[u][p][j] + *trans.rbegin());

                trans.insert(dp1[v][opp_c]);
            }
        }
    }
    cout << ans << '\n';
    
}

Compilation message

chase.cpp: In function 'int main()':
chase.cpp:94:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   94 |             for (int j = 0; j < children[u].size(); j++) {
      |                             ~~^~~~~~~~~~~~~~~~~~~~
chase.cpp:104:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  104 |             for (int j = 0; j < children[u].size(); j++) {
      |                             ~~^~~~~~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 15960 KB Output is correct
2 Correct 3 ms 16016 KB Output is correct
3 Correct 4 ms 15964 KB Output is correct
4 Correct 4 ms 15964 KB Output is correct
5 Correct 4 ms 15964 KB Output is correct
6 Correct 3 ms 16008 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 15960 KB Output is correct
2 Correct 3 ms 16016 KB Output is correct
3 Correct 4 ms 15964 KB Output is correct
4 Correct 4 ms 15964 KB Output is correct
5 Correct 4 ms 15964 KB Output is correct
6 Correct 3 ms 16008 KB Output is correct
7 Correct 28 ms 18268 KB Output is correct
8 Correct 8 ms 18264 KB Output is correct
9 Correct 6 ms 18268 KB Output is correct
10 Correct 23 ms 18112 KB Output is correct
11 Correct 10 ms 18008 KB Output is correct
12 Correct 7 ms 18268 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3618 ms 116888 KB Output is correct
2 Correct 3719 ms 116916 KB Output is correct
3 Execution timed out 4067 ms 118600 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 15960 KB Output is correct
2 Correct 3 ms 16016 KB Output is correct
3 Correct 4 ms 15964 KB Output is correct
4 Correct 4 ms 15964 KB Output is correct
5 Correct 4 ms 15964 KB Output is correct
6 Correct 3 ms 16008 KB Output is correct
7 Correct 28 ms 18268 KB Output is correct
8 Correct 8 ms 18264 KB Output is correct
9 Correct 6 ms 18268 KB Output is correct
10 Correct 23 ms 18112 KB Output is correct
11 Correct 10 ms 18008 KB Output is correct
12 Correct 7 ms 18268 KB Output is correct
13 Correct 3618 ms 116888 KB Output is correct
14 Correct 3719 ms 116916 KB Output is correct
15 Execution timed out 4067 ms 118600 KB Time limit exceeded
16 Halted 0 ms 0 KB -