Submission #225743

#	Time	Username	Problem	Language	Result	Execution time	Memory
225743		osaaateiasavtnl	Mag (COCI16_mag)	C++14	120 / 120	653 ms	252664 KiB

mag

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ii pair <int, int>
#define app push_back
#define all(a) a.begin(), a.end()
#define bp __builtin_popcount
#define ll long long
#define mp make_pair
#define f first
#define s second
#define Time (double)clock()/CLOCKS_PER_SEC

const int N = 1e6 + 7, INF = 1e9 + 7;
int n, a[N];
vector <int> g[N];
int x, y;
void relax(int a, int b) {
    if (a * y < x * b) {
        x = a;
        y = b;
    }   
}   
int down[N];
void dfs1(int u, int p) {
    down[u] = a[u] == 1;
    for (int v : g[u]) {
        if (v != p) {
            dfs1(v, u);
            if (a[u] == 1)
                down[u] = max(down[u], down[v] + 1);            
        }   
    }   
}   
int up[N];
void dfs2(int u, int p) {
    vector <int> d = {0, 0};
    for (int v : g[u]) {
        if (v != p) {
            d.app(down[v]);
        }   
    }
    sort(all(d));                                    
    reverse(all(d));
    for (int v : g[u]) {
        if (v != p) {
            if (a[u] != 1) {
                up[v] = 0;
            }
            else {
                int h = d[d[0] == down[v]];
                up[v] = max(up[u], h) + 1;
            }
            dfs2(v, u);
        }   
    }   
    relax(a[u], d[0] + d[1] + 1);
    relax(a[u], up[u] + d[0] + 1);
}   
signed main() {
    #ifdef HOME
    freopen("input.txt", "r", stdin);
    #else
    #define endl '\n'
    ios_base::sync_with_stdio(0); cin.tie(0);
    #endif
    cin >> n;
    for (int i = 0; i < n - 1; ++i) {
        int u, v;
        cin >> u >> v;
        g[u].app(v); g[v].app(u);
    }   
    x = INF;
    y = 1;
    for (int i = 1; i <= n; ++i) {
        cin >> a[i];
        relax(a[i], 1);
    }
    dfs1(1, 1);
    dfs2(1, 1);

    int t = __gcd(x, y);
    x /= t; y /= t;

    cout << x << '/' << y << endl;
}

• Subtask 1: 12 / 12
• Subtask 2: 12 / 12
• Subtask 3: 12 / 12
• Subtask 4: 12 / 12
• Subtask 5: 12 / 12
• Subtask 6: 12 / 12
• Subtask 7: 12 / 12
• Subtask 8: 12 / 12
• Subtask 9: 12 / 12
• Subtask 10: 12 / 12