牛客国庆集训派对Day3 B Tree

#pragma comment(linker, "/STACK:102400000,102400000")
#include<unordered_map>
#include<unordered_set>
#include<algorithm>
#include<iostream>
#include<fstream>
#include<complex>
#include<cstdlib>
#include<cstring>
#include<cassert>
#include<iomanip>
#include<string>
#include<cstdio>
#include<bitset>
#include<vector>
#include<cctype>
#include<cmath>
#include<ctime>
#include<stack>
#include<queue>
#include<deque>
#include<list>
#include<set>
#include<map>
using namespace std;
#define pt(a) cout<<a<<endl
#define debug test
#define mst(ss,b) memset((ss),(b),sizeof(ss))
#define rep(i,a,n) for (int i=a;i<=n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define fi first
#define se second
#define ll long long
#define ull unsigned long long
#define pb push_back
#define mp make_pair
#define inf 0x3f3f3f3f
#define eps 1e-10
#define PI acos(-1.0)
const ll mod = 1e9+7;
const int N = 1e6+10;ll qp(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
int to[4][2]={{-1,0},{1,0},{0,-1},{0,1}};ll n,ct[N],_ct[N];
vector<int> e[N];void dfs(int fa,int x) {ct[x]=1;for(int i=0;i<e[x].size();i++) {int u=e[x][i];if(u!=fa) {dfs(x,u);ct[x]=ct[x]*(ct[u]+1)%mod;}}
}void DFS(int fa,int x) {for(int i=0;i<e[x].size();i++) {int u=e[x][i];if(u!=fa) {ll tp=1;if( (ct[u]+1)!=mod ) tp=ct[x]*qp(ct[u]+1,mod-2)%mod;else {for(int j=0;j<e[x].size();j++) {///为0特判int uu=e[x][j];if(uu!=u&&uu!=fa) tp=tp*(ct[uu]+1)%mod;}}_ct[u]=(_ct[x]*tp+1)%mod;DFS(x,u);}}
}int main() {ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);while(cin>>n) {int a,b;for(int i=1;i<n;i++) cin>>a>>b,e[a].pb(b),e[b].pb(a);dfs(0,1);_ct[1]=1;DFS(0,1);for(int i=1;i<=n;i++) cout<<ct[i]*_ct[i]%mod<<endl;for(int i=1;i<=n;i++) e[i].clear();}return 0;
}