Submission #931605

#	Time	Username	Problem	Language	Result	Execution time	Memory
931605		vjudge1	Capital City (JOI20_capital_city)	C++17	11 / 100	223 ms	6100 KiB

capital_city

#include <bits/stdc++.h>
using namespace std;

#ifdef DEBUG
#include "debug.h"
#else
#define debug(...) 0
#endif

typedef long long ll;

const int N = 2e3 + 4;

int n, k, c[N], cnt[N];
bool have[N], seen[N];
vector<int> T[N], D[N];

void dfs1(int v, int p) {
    have[c[v]] = 1;
    for (int u : T[v]) {
        if (u != p) {
            dfs1(u, v);
        }
    }
}

void dfs2(int v) {
    seen[v] = 1;
    for (int u : D[v]) {
        if (seen[u] == 0) {
            dfs2(u);
        }
    }
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    cin >> n >> k;
    for (int i = 1; i < n; i++) {
        int v, u;
        cin >> v >> u;
        v--; u--;
        T[v].push_back(u);
        T[u].push_back(v);
    }
    for (int i = 0; i < n; i++) {
        cin >> c[i];
        c[i]--;
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cnt[j] = have[j] = 0;
        }
        for (int v : T[i]) {
            dfs1(v, i);
            for (int j = 0; j < n; j++) {
                cnt[j] += have[j];
                have[j] = 0;
            }
        }
        for (int j = 0; j < k; j++) {
            if (cnt[j] >= 2) {
                D[j].push_back(c[i]);
            }
        }
    }

    int ans = k;
    for (int i = 0; i < k; i++) {
        for (int j = 0; j < k; j++) {
            seen[j] = 0;
        }
        dfs2(i);
        
        int cand = 0;
        for (int j = 0; j < k; j++) {
            cand += seen[j];
        }
        ans = min(ans, cand);
    }
    cout << ans - 1;

    return 0;
}

• Subtask 1: 1 / 1
• Subtask 2: 10 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 59