oj.uz

Submission #230640

# Submission time Handle Problem Language Result Execution time Memory
230640 2020-05-10T16:58:51 Z WLZ Capital City (JOI20_capital_city) C++14
11 / 100
 3000 ms 43768 KB 
#include "bits/stdc++.h"
using namespace std;

const int INF = 0x3f3f3f3f;

int k, ans = INF;
vector< vector<int> > g, towns;
vector<int> c, sz, par, cur;
vector<bool> used;

void dfs(int u, int p) {
    sz[u] = 1; par[u] = p;
    cur.push_back(u);
    for (auto& v : g[u]) {
        if (v != p && !used[v]) {
            dfs(v, u);
            sz[u] += sz[v];
        }
    }
}

int find_centroid(int u, int p, int n) {
    for (auto& v : g[u]) {
        if (v != p && sz[v] > n / 2 && !used[v]) {
            return find_centroid(v, u, n);
        }
    }
    return u;
}

void solve(int u) {
    dfs(u, -1);
    int centroid = find_centroid(u, -1, sz[u]);
    cur.clear();
    dfs(centroid, -1);
    vector<int> cnt(k + 1);
    for (auto& x : cur) {
        cnt[c[x]]++;
    }
    set<int> st;
    if (cnt[c[centroid]] == (int)towns[c[centroid]].size()) {
        bool pos = true;
        queue<int> q;
        for (auto& x : towns[c[centroid]]) {
            q.push(x);
        }
        st.insert(c[centroid]);
        while (!q.empty()) {
            int x = q.front(); q.pop();
            if (x != centroid && !st.count(c[par[x]])) {
                if (cnt[c[par[x]]] != (int)towns[c[par[x]]].size()) {
                    pos = false;
                    break;
                }
                for (auto& y : towns[c[par[x]]]) {
                    q.push(y);
                }
                st.insert(c[par[x]]);
            }
        }
        if (pos) {
            ans = min(ans, (int) st.size());
        }
    }
    used[centroid] = true;
    for (auto& v : g[centroid]) {
        if (!used[v]) {
            solve(v);
        }
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n >> k;
    g.resize(n + 1);
    for (int i = 0; i < n - 1; i++) {
        int a, b;
        cin >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    c.resize(n + 1);
    towns.resize(k + 1);
    for (int i = 1; i <= n; i++) {
        cin >> c[i];
        towns[c[i]].push_back(i);
    }
    par.resize(n + 1);
    sz.resize(n + 1);
    used.assign(n + 1, false);
    solve(1);
    cout << ans - 1 << '\n';
    return 0;
}

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 5 ms 384 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 5 ms 384 KB Output is correct
11 Correct 7 ms 512 KB Output is correct
12 Correct 7 ms 640 KB Output is correct
13 Correct 7 ms 512 KB Output is correct
14 Correct 7 ms 512 KB Output is correct
15 Correct 7 ms 640 KB Output is correct
16 Correct 7 ms 640 KB Output is correct
17 Correct 7 ms 640 KB Output is correct
18 Correct 7 ms 640 KB Output is correct
19 Correct 7 ms 640 KB Output is correct
20 Correct 7 ms 640 KB Output is correct
21 Correct 7 ms 640 KB Output is correct
22 Correct 8 ms 768 KB Output is correct
23 Correct 7 ms 640 KB Output is correct
24 Correct 8 ms 640 KB Output is correct
25 Correct 8 ms 640 KB Output is correct
26 Correct 8 ms 640 KB Output is correct
27 Correct 8 ms 640 KB Output is correct
28 Correct 7 ms 640 KB Output is correct
29 Correct 8 ms 640 KB Output is correct
30 Correct 7 ms 640 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Execution timed out 3076 ms 43768 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 59.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 5 ms 384 KB Output is correct
11 Correct 7 ms 512 KB Output is correct
12 Correct 7 ms 640 KB Output is correct
13 Correct 7 ms 512 KB Output is correct
14 Correct 7 ms 512 KB Output is correct
15 Correct 7 ms 640 KB Output is correct
16 Correct 7 ms 640 KB Output is correct
17 Correct 7 ms 640 KB Output is correct
18 Correct 7 ms 640 KB Output is correct
19 Correct 7 ms 640 KB Output is correct
20 Correct 7 ms 640 KB Output is correct
21 Correct 7 ms 640 KB Output is correct
22 Correct 8 ms 768 KB Output is correct
23 Correct 7 ms 640 KB Output is correct
24 Correct 8 ms 640 KB Output is correct
25 Correct 8 ms 640 KB Output is correct
26 Correct 8 ms 640 KB Output is correct
27 Correct 8 ms 640 KB Output is correct
28 Correct 7 ms 640 KB Output is correct
29 Correct 8 ms 640 KB Output is correct
30 Correct 7 ms 640 KB Output is correct
31 Execution timed out 3076 ms 43768 KB Time limit exceeded
32 Halted 0 ms 0 KB -