제출 #703253

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
703253		Makarooni	Mag (COCI16_mag)	C++17	120 / 120	891 ms	182192 KiB

mag

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

#define pb(x) push_back(x)
#define sz(x) (int)x.size()
typedef long long ll;
typedef long double ld;

const int N = 1e6 + 10;
const int inf = 1e9 + 1;

vector<int> g[N];
int a[N], d[N], x[N], P, Q, d2[N];

void dfs2(int v, int p){
    if(a[v] == 1)
        d[v] = 1;
    int mx1 = 0, mx2 = 0;
    for(int j = 0; j < sz(g[v]); j++){
        int u = g[v][j];
        if(u == p)
            continue;
        dfs2(u, v);
        if(a[u] != 1)
            continue;
        d[v] = max(d[v], d[u] + (a[v] == 1));
        if(d[u] > mx1){
            mx2 = mx1;
            mx1 = d[u];
        }
        else if(d[u] > mx2)
            mx2 = d[u];
    }
    x[v] = max(mx1 + mx2 + (a[v] == 1), d[v]);
}

void dfs3(int v, int p){
    int mx1 = -1, mx2 = -1, V = -1;
    for(int j = 0; j < sz(g[v]); j++){
        int u = g[v][j];
        if(u == p)
            continue;
        if(a[u] == 1){
            if(d[u] > mx1){
                V = u;
                mx2 = mx1;
                mx1 = d[u];
            }
            else if(d[u] > mx2)
                mx2 = d[u];
        }
        if(a[v] == 1)
            d2[u] = max(d2[u], d2[v] + (a[v] == 1));
        dfs3(u, v);
    }
    for(int j = 0; j < sz(g[v]); j++){
        int u = g[v][j];
        if(u == p)
            continue;
        int w = mx1;
        if(u == V)
            w = mx2;
        if(a[v] == 1)
            x[u] = max(x[u], w + (a[v] == 1) + d[u]);
    }
    x[v] = max(x[v], d2[v] + d[v]);
}

int main() {
    int n;
    cin >> n;
    int u, v;
    for(int i = 1; i < n; i++){
        cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
    }
    int mn = inf;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        mn = min(mn, a[i]);
    }
    if(mn != 1){
        cout << mn << "/1";
        return 0;
    }
    ld ans = 1;
    dfs2(1, 0);
    dfs3(1, 0);
    for(int i = 1; i <= n; i++){
        ld tmp = ld(a[i]) / ld(x[i] + (a[i] != 1));
        if(tmp < ans){
            ans = tmp;
            P = a[i];
            Q = x[i] + (a[i] != 1);
        }
    }
    int G = __gcd(P, Q);
    P /= G;
    Q /= G;
    cout << P << "/" << Q;
}

• 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