Submission #1230620

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Source Code Expand

#include <bits/stdc++.h>
 
#define _overload(_1,_2,_3,name,...) name
#define _rep(i,n) _range(i,0,n)
#define _range(i,a,b) for(int i=(int)(a);i<(int)(b);++i)
#define rep(...) _overload(__VA_ARGS__,_range,_rep,)(__VA_ARGS__)
 
#define _rrep(i,n) _rrange(i,n,0)
#define _rrange(i,a,b) for(int i=(int)(a)-1;i>=(int)(b);--i)
#define rrep(...) _overload(__VA_ARGS__,_rrange,_rrep,)(__VA_ARGS__)
 
#define _all(arg) begin(arg),end(arg)
#define uniq(arg) sort(_all(arg)),(arg).erase(unique(_all(arg)),end(arg))
#define getidx(ary,key) lower_bound(_all(ary),key)-begin(ary)
#define clr(a,b) memset((a),(b),sizeof(a))
#define bit(n) (1LL<<(n))
 
// #define DEBUG
 
#ifdef DEBUG
    #define dump(...) fprintf(stderr, __VA_ARGS__)
#else
    #define dump(...)
#endif
 
template<class T>bool chmax(T &a, const T &b) { return (a<b)?(a=b,1):0;}
template<class T>bool chmin(T &a, const T &b) { return (b<a)?(a=b,1):0;}
 
using namespace std;
using ll=long long;
using vi=vector<int>;
using vll=vector<ll>;
 
const double EPS = 1e-10;
const double PI = acos(-1.0);
const ll inf =1LL << 62;
const ll mod=1000000007LL;
const int dx[4]={1,0,-1,0};
const int dy[4]={0,1,0,-1};
 
 
ll extgcd(ll a,ll b,ll& x,ll& y){x=1,y=0;ll g=a;if(b!=0) g=extgcd(b,a%b,y,x),y-=a/b*x;return g;}
ll ADD(const ll &a, const ll &b,const ll &mod) { return (a+b)%mod;}
ll SUB(const ll &a, const ll &b,const ll &mod) { return (a-b+mod)%mod;}
ll MUL(const ll &a, const ll &b,const ll &mod) { return (1LL*a*b)%mod;}
ll DIV(const ll &a, const ll &b,const ll &mod) {ll x,y; extgcd(b,mod,x,y);return MUL(a,(x+mod)%mod,mod);}
 
random_device rd;
mt19937 mt(rd());
uniform_int_distribution<int> dice(1,6);
uniform_real_distribution<double> score(0.0,10.0);

using R = double;
vector<R> dp1, dp2;
vector<vi> graph;

R dfs1(int v, int pv){
    R& cur = dp1[v];
    cur = (R)0;

    int cnt = 0;
    for(auto& nv : graph[v]){
        if(nv == pv) continue;

        cur += (dfs1(nv, v) + 1);
        cnt++;
    }
    if(cnt > 0) cur /= (graph[v].size() - 1);

    return cur;
}

R dfs2(int v, int pv, R par_val){
    R& cur = dp2[v];
    cur = par_val + (pv != -1 ? 1:0);

    int cnt = (pv != -1 ? 1:0);
    for(auto& nv : graph[v]){
        if(nv == pv) continue;
        cur += (dp1[nv] + 1);
        cnt++;
    }
    cur /= cnt;

    for(auto& nv : graph[v]){
        if(nv == pv) continue;
        R nval = cur * cnt;
        nval -= (dp1[nv] + 1);
        if(cnt - 1 > 0) nval /= (cnt - 1);
        dfs2(nv, v, nval);
    }

    return cur;
}

int main(void){
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n; cin >> n;
    if(n == 1){
        cout << 0 << endl;
        return 0;
    }

    dp1 = dp2 = vector<R>(n, -1);
    graph = vector<vi>(n);
    rep(loop, n - 1){
        int u, v; cin >> u >> v;
        u--, v--;
        graph[u].emplace_back(v);
        graph[v].emplace_back(u);
    }

    dfs1(0, -1);
    dfs2(0, -1, 0.0);

    cout.precision(20);
    rep(i, n){
        cout << fixed << dp2[i] << endl;
    }

    return 0;
}

Submission Info

Judge Result