제출 #245733

#제출 시각아이디문제언어결과실행 시간메모리
245733Vladikus004Mag (COCI16_mag)C++14
24 / 120
478 ms130296 KiB
#include <bits/stdc++.h>
#define inf 2e9
#define all(v) v.begin(), v.end()
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair <int, int> pii;

const int N = 1000000 + 3;
int n, x[N], d[N], dp[N], p[N], ans;
vector <vector <int> > v;

void dfs(int x){
    pii mx = {0, 0};
    p[x] = 1;
    for (auto u: v[x]){
        if (p[u]) continue;
        dfs(u);
        mx = max(mx, {mx.first, dp[u]});
        mx = max(mx, {dp[u], mx.first});
        dp[x] = max(dp[x], dp[u]);
    }
    if (d[x]) {
        dp[x]++;
        ans = max(ans, mx.first + mx.second + 1);
    }else dp[x] = 0;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    #ifdef LOCAL
        freopen("input.txt", "r", stdin);
    #endif // LOCAL
    cin >> n;
    v.resize(n);
    for (int i = 0; i < n - 1; i++){
        int a, b;
        cin >> a >> b;
        --a; --b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for (int i = 0; i < n; i++){
        cin >> x[i];
        if (x[i] == 1)
            d[i] = 1;
    }
    dfs(0);
    if (!ans){
        ans = inf;
        for (int i = 0; i < n; i++)
            ans = min(ans, x[i]);
        cout << ans << "/1";
        return 0;
    }
    cout << "1/" << ans;
}
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...