Submission #212589

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
212589	2020-03-23T17:20:11 Z	toxic_hack	Mag (COCI16_mag)	C++14	120 / 120	1770 ms	262144 KB

// g++ -std=c++14

/*

Today might be the chance to grasp the chance to let your talent bloom.
May be tomorrow, the day after, or next year...
May be even when you are 30. I'm not sure if physique has anything to do with it
but if you think that it will never come, it probably never will.

- Tooru Oikawa.

*/
#include<bits/stdc++.h>

typedef long long ll;
typedef long double lld;
using namespace std;

#define endl "\n"
#define fi first
#define se second
#define pb(x) push_back(x)
#define mp(x,y) make_pair(x,y)
#define MEMS(a,b) memset(a,b,sizeof(a))
#define _ ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define __ freopen("input.txt","r",stdin);freopen("output.txt","w",stdout);
#define all(c) c.begin(),c.end()
#define pii pair<int, int>
#define tr(...) cout<<__FUNCTION__<<' '<<__LINE__<<" = ";trace(#__VA_ARGS__, __VA_ARGS__)
template<typename S, typename T>
ostream& operator<<(ostream& out,pair<S,T> const& p){out<<'('<<p.fi<<", "<<p.se<<')';return out;}

template<typename T>
ostream& operator<<(ostream& out,vector<T> const& v){
ll l=v.size();for(ll i=0;i<l-1;i++)out<<v[i]<<' ';if(l>0)out<<v[l-1];return out;}

template <typename T>
ostream &operator<<(ostream &out, set<T> const &v) {
    for (auto i = v.begin(); i != v.end(); i++)
        out << (*i) << ' ';
    return out;
}
template <typename T, typename V>
ostream &operator<<(ostream &out, map<T, V> const &v) {
    for (auto i = v.begin(); i != v.end(); i++)
        out << "\n" << (i->first) <<  ":"  << (i->second);
    return out;
}

template<typename T>
void trace(const char* name, T&& arg1){cout<<name<<" : "<<arg1<<endl;}

template<typename T, typename... Args>
void trace(const char* names, T&& arg1, Args&&... args){
const char* comma = strchr(names + 1, ',');cout.write(names, comma-names)<<" : "<<arg1<<" | ";trace(comma+1,args...);}

// #define int ll

const int N = 1e6 + 100;

int n;
vector<int> g[N];
int arr[N];

int dp_down[N], dp_up[N];
int parent[N];
int ans0 = 0;

void setabc(int &a, int &b, int c) {
    if (c > a) {
        b = a;
        a = c;
    } else if (c > b) {
        b = c;
    }
}

void dfs0(int v, int p) {
     parent[v] = p;
    int curr = (arr[v] == 1);
    int a = 0, b = 0;
    for (auto u : g[v]) {
        if (u == p)  continue;
        dfs0(u, v);
        curr = max(curr, dp_down[u] + 1);
        setabc(a, b, dp_down[u]);
    }
    if (arr[v] == 1) {
        dp_down[v] = curr;
        ans0 = max(ans0, a + b + 1);
    }
}

void dfs1(int v, int p, int mx_len = 0) {
    // tr(v, mx_len);
    dp_up[v] = mx_len;
    if (arr[v] == 1) {
        multiset<int> child;
        child.insert(mx_len);
        for (auto u : g[v]) {
            if (u == p) continue;
            child.insert(dp_down[u]);
        }

        for (auto u : g[v]) {
            if (u == p) continue;
            child.erase(child.find(dp_down[u]));
            int heremx = *child.rbegin() + 1;
            dfs1(u, v, heremx);
            child.insert(dp_down[u]);
        }

    } else {
        for (auto u : g[v]) {
            if (u == p) continue;
            dfs1(u, v, 0);
        }
    }
}

int cmp(int a, int b, int c, int d) {
    return (1LL * a * d < 1LL * c * b);
}

const int inf = 1e9 + 1;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r)
{
	uniform_int_distribution<int> uid(l, r);
	return uid(rng);
}


void gen() {
    n = rand(1e5, 1e5);
    // vector<int> curr = {0};
    // vector<int> parent(n + 1);
    // for (int i = 1; i <= n; i++) {
    //     int kk = curr.size();
    //     // int p = curr[rand(0, kk - 1)];
    //     int p = curr.back();
    //     parent[i] = p;
    //     curr.push_back(i);
    //     if (i > 1) {
    //         g[parent[i]].push_back(i);
    //         g[i].push_back(parent[i]);
    //     }
    // }
    for (int i = 2; i <= n; i++) {
        g[i].push_back(i - 1);
        g[i - 1].push_back(i);
    }
    for (int i = 1; i <= n; i++) {
        int temp = rand(1, 10);
        if (temp > 5) {
            arr[i] = rand(1, 1e9);
        } else {
            arr[i] = 1;
        }
        // arr[i] = rand(1, 1);
    }
    // tr(n);
    cout << n << endl;
}

int solve() {
    cin >> n;
    for (int i = 0; i < n - 1; i++) {
        int v, u;
        cin >> v >> u;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    for (int i = 1; i <= n; i++) {
        cin >> arr[i];
    }
    // gen();
    dfs0(1, 0);
    dfs1(1, 0);

    if (ans0 == 0) {
        int mi = inf;
        for (int i = 1; i <= n; i++) {
            mi = min(mi, arr[i]);
        }
        cout << mi << "/1" << endl;
    } else {
        int a = 1, b = ans0;
        for (int i = 1; i <= n; i++) {
            vector<int> pth;
            for (auto j : g[i]) {
                if (j == parent[i]) continue;
                pth.push_back(dp_down[j]);
            }
            pth.push_back(dp_up[i]);
            sort(all(pth));
            reverse(all(pth));
            // tr(i, pth, a, b);
            if ((int)pth.size() == 1) {
                int c = arr[i], d = pth[0] + 1;
                if (!cmp(a, b, c, d)) {
                    a = c, b = d;
                }
            } else {
                int c = arr[i], d = 1 + pth[0] + pth[1];
                if (!cmp(a, b, c, d)) {
                    a = c, b = d;
                }
            }
        }
        assert(b != 0 && a != 0);
        int g = __gcd(a, b);
        a /= g;
        b /= g;
        cout << a << "/" << b << endl;
    }
    return 0;
}

int32_t main(){ 
    int t;
    // cin >> t;
    t = 1;
    while (t--) solve();
}

Subtask #1
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	18 ms	23936 KB	Output is correct
2	Correct	18 ms	23936 KB	Output is correct

Subtask #2
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	18 ms	23936 KB	Output is correct
2	Correct	18 ms	23936 KB	Output is correct

Subtask #3
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1407 ms	150536 KB	Output is correct

Subtask #4
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	18 ms	23808 KB	Output is correct
2	Correct	1597 ms	248696 KB	Output is correct

Subtask #5
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1752 ms	262144 KB	Output is correct

Subtask #6
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1503 ms	85880 KB	Output is correct
2	Correct	1122 ms	70008 KB	Output is correct

Subtask #7
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1510 ms	92136 KB	Output is correct
2	Correct	211 ms	30200 KB	Output is correct
3	Correct	1770 ms	262144 KB	Output is correct

Subtask #8
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	194 ms	29944 KB	Output is correct
2	Correct	1481 ms	87672 KB	Output is correct
3	Correct	944 ms	55560 KB	Output is correct

Subtask #9
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1448 ms	85448 KB	Output is correct
2	Correct	1552 ms	87160 KB	Output is correct

Subtask #10
12.0 / 12.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1557 ms	87544 KB	Output is correct
2	Correct	941 ms	55544 KB	Output is correct

Submission #212589

Compilation message