Submission #960868

# Submission time Handle Problem Language Result Execution time Memory
960868 2024-04-11T06:55:37 Z Ghetto Chase (CEOI17_chase) C++17
40 / 100
329 ms 524288 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][MAX_K];
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 <= k; 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++) {
        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]][c][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]][c - 1][adj_ind[u][i]]);
            for (int i = 1; i < adj[u].size(); i++)
                if (i != prev) take += val[adj[u][i]];
            
            dp[u][c][prev] = max(take, leave);
        }
    }

    lint ans = 0;
    for (int i = 1; i <= n; i++) ans = max(ans, dp[i][k][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:71:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |             for (int i = 1; i < adj[u].size(); i++)
      |                             ~~^~~~~~~~~~~~~~~
chase.cpp:75:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |             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++)
      |                             ~~^~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 58 ms 254036 KB Output is correct
2 Correct 58 ms 254056 KB Output is correct
3 Correct 59 ms 254032 KB Output is correct
4 Correct 59 ms 254032 KB Output is correct
5 Correct 58 ms 253932 KB Output is correct
6 Correct 59 ms 254044 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 58 ms 254036 KB Output is correct
2 Correct 58 ms 254056 KB Output is correct
3 Correct 59 ms 254032 KB Output is correct
4 Correct 59 ms 254032 KB Output is correct
5 Correct 58 ms 253932 KB Output is correct
6 Correct 59 ms 254044 KB Output is correct
7 Correct 70 ms 259528 KB Output is correct
8 Correct 61 ms 254544 KB Output is correct
9 Correct 81 ms 254428 KB Output is correct
10 Correct 75 ms 259472 KB Output is correct
11 Correct 65 ms 255712 KB Output is correct
12 Correct 61 ms 254556 KB Output is correct
# Verdict Execution time Memory Grader output
1 Runtime error 329 ms 524288 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 58 ms 254036 KB Output is correct
2 Correct 58 ms 254056 KB Output is correct
3 Correct 59 ms 254032 KB Output is correct
4 Correct 59 ms 254032 KB Output is correct
5 Correct 58 ms 253932 KB Output is correct
6 Correct 59 ms 254044 KB Output is correct
7 Correct 70 ms 259528 KB Output is correct
8 Correct 61 ms 254544 KB Output is correct
9 Correct 81 ms 254428 KB Output is correct
10 Correct 75 ms 259472 KB Output is correct
11 Correct 65 ms 255712 KB Output is correct
12 Correct 61 ms 254556 KB Output is correct
13 Runtime error 329 ms 524288 KB Execution killed with signal 9
14 Halted 0 ms 0 KB -