답안 #246055

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
246055 2020-07-08T05:57:44 Z leaked Mag (COCI16_mag) C++14
48 / 120
607 ms 172620 KB
#include<bits/stdc++.h>
using namespace std;
//#include<ext/pb_ds/assoc_container.hpp>
//#include<ext/pb_ds/tree_policy.hpp>
//
//    #pragma GCC optimize("unroll-loops")
//    #pragma GCC optimize("Ofast")
//    #pragma GCC optimize("-O3")
//    #pragma GCC optimize("no-stack-protector")
//    #pragma GCC optimize("fast-math")
//#define LOCAL
#define sim template < class c
#define ris return * this
#define dor > debug & operator <<
#define eni(x) sim > typename \
  enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i) {
sim > struct rge { c b, e; };
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c* x) -> decltype(cout<< *x, 0);
sim > char dud(...);
struct debug {
#ifndef LOCAL
~debug() { cout << endl; }
eni(!=) cout << boolalpha << i; ris; }
eni(==) ris << range(begin(i), end(i)); }
sim, class b dor(pair < b, c > d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
	*this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
sim dor(const c&) { ris; }
#endif
};
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
#define fi first
#define f first
#define se second
#define s second
#define vi_a vector<int>a;
#define p_b push_back
////////////////////////////////???????????????CHECK THIS OUT???????????????//////////////////////////////
#define ll long long
////////////////////////////////???????????????CHECK THIS OUT???????????????//////////////////////////////
#define ld long double
#define pll pair<ll,ll>
#define pii pair<int,int>
#define m_p make_pair
#define fast_io cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(0);
#define all(x) x.begin(),x.end()
#define getfiles    ifstream cin("input.txt");ofstream cout("output.txt");
#define pw(x) (1ll << x)
#define sz(x) (ll)x.size()
#define endl "\n"
#define rall(x) x.rbegin(),x.rend()
#define len(a) (ll)a.size()
#define rep(x,l,r) for(ll x=l;x<r;x++)

//using namespace __gnu_pbds;
ld eps = (ld)1 / 1e6;
const ld pi=3.14159265359;
ll inf = 1e18,mod1=1e9+7;
ll sqr(ll a) { return a * a; }
ll qb(ll a) { return a * a * a; }
ll gcd(ll a, ll b) { return !a ? b : gcd(b % a, a); }
ll binpow(ll a, ll b, ll mod) { return b ? (b % 2 ? (a * (sqr(binpow(a, b / 2, mod)) % mod)) % mod : sqr(binpow(a, b / 2, mod)) % mod) : 1; }
ll binmult(ll a, ll b, ll mod) { return b ? (b % 2 ? (2 * binmult(a, b / 2, mod) + a) % mod : (2 * binmult(a, b / 2, mod)) % mod) : 0; }
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
const ll R=1e4;
const ll tx[4]={0,0,-1,1};
const ll ty[4]={-1,1,0,0};
const char rev_to[4]={'E','W','N','S'};
const int N=2e6+1;
const int M=999999937;
ll a[N];
int n,v,u;
pll ans={1e18,1};
ll f[N];
vector<int>g[N];
void dfs(int v,int p){
    f[v]=a[v]==1;
    for(auto &z :g[v]){
        if(z^p){
            dfs(z,v);
            if(a[v]==1) f[v]=max(f[v],f[z]+1);
        }
    }
}
bool cmp(pll a,pll b){
    ld l=(ld) a.f/a.s,r=(ld)b.f/b.s;
    return l<r;
}
ll ff=0,s=0;
void dfs1(int v,int p,ll to){
  //  ans=min(ans,{a[v],1});
    if(cmp({a[v],1},ans))ans={a[v],1};
    ll mx=to;
//    debug()<<imie(to)<<imie(v)<<imie(ans)<<imie(f[v]);
    for(auto &z :g[v]){
        if(z^p){
            if(a[v]<=2){
                if(cmp({a[v],1+mx+f[z]},ans)) ans={a[v],1+mx+f[z]};
//                debug()<<imie(to)<<imie(v)<<imie(ans)<<imie(f[v]);
                if(a[v]==1)ff=max(ff,mx+1+f[z]);
                mx=max(mx,f[z]);
            }
            if(a[v]==2){
//                cout<<"F"<<a[v]<<' '<<1+mx+f[z]<<endl;
                s=max(s,mx+1+f[z]);
//                cout.flush();

            }
            dfs1(z,v,(a[v]==1 ? to+1 : 0));
        }
    }
}
signed main(){
    fast_io;
//    freopen("5.in","r",stdin);
    cin>>n;
    for(int i=1;i<n;i++){
        cin>>v>>u;--v;--u;
        g[v].p_b(u);g[u].p_b(v);
    }
    for(int i=0;i<n;i++) cin>>a[i];
    dfs(0,0);
    dfs1(0,0,0);
    if(ff && s){
        if(2*ff<s){
            ans={2,s};
        }
        else{
            ans={1,ff};
        }
    }
    ll gc=__gcd(ans.f,ans.s);
    cout<<ans.f/gc<<'/'<<ans.s/gc;
    return 0;
}
///stuff you should look for :
/*
	* int overflow, array bounds
	* special cases (n=1?)
	* do smth instead of nothing and stay organized
	* read the conditions carefully
	* WRITE STUFF DOWN
*/
# 결과 실행 시간 메모리 Grader output
1 Correct 34 ms 47352 KB Output is correct
2 Incorrect 31 ms 47360 KB Output isn't correct
# 결과 실행 시간 메모리 Grader output
1 Correct 32 ms 47360 KB Output is correct
2 Incorrect 37 ms 47368 KB Output isn't correct
# 결과 실행 시간 메모리 Grader output
1 Correct 443 ms 117428 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 33 ms 47360 KB Output is correct
2 Incorrect 558 ms 172620 KB Output isn't correct
# 결과 실행 시간 메모리 Grader output
1 Correct 568 ms 170680 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 487 ms 94980 KB Output is correct
2 Incorrect 358 ms 83040 KB Output isn't correct
# 결과 실행 시간 메모리 Grader output
1 Correct 458 ms 95692 KB Output is correct
2 Correct 111 ms 52856 KB Output is correct
3 Correct 607 ms 172508 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 110 ms 52092 KB Output is correct
2 Correct 447 ms 94760 KB Output is correct
3 Correct 400 ms 71304 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Incorrect 423 ms 91248 KB Output isn't correct
2 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Incorrect 466 ms 94712 KB Output isn't correct
2 Halted 0 ms 0 KB -