F-小红的树上赋值（hard）_牛客周赛 Round 41 (nowcoder.com)

from types import GeneratorType
from collections import defaultdict

def bootstrap(f, stack=[]):
    def wrappedfunc(*args, **kwargs):
        if stack:
            return f(*args, **kwargs)
        else:
            to = f(*args, **kwargs)
            while True:
                if type(to) is GeneratorType:
                    stack.append(to)
                    to = next(to)
                else:
                    stack.pop()
                    if not stack:
                        break
                    to = stack[-1].send(to)
            return to
    return wrappedfunc

n,l,r=map(int,input().split())

col="#"+input()

g=[[] for _ in range(n+1)]
d=[[] for _ in range(n+1)]
res=[0]*(n+1)

for _ in range(n-1):
    u,v=map(int,input().split())
    g[u]+=[v]
    g[v]+=[u]

@bootstrap
def dfs(u,fa,top):
    ntop=u if col[u]=="R" else top
    d[ntop].append(u)    
    for v in g[u]:
        if v==fa:
            continue
        yield dfs(v,u,ntop)
    yield None
dfs(1,-1,0)

mx=r if r>abs(l) else l
for i in d[0]:
    res[i]=mx

def check(mid,t):
    k=(mid+r-1)//r
    return k<t and (t-k)*abs(l)>=mid

for x in range(1,n+1):
    t=len(d[x])
    if t<2:
        continue
    ll=0
    rr=int(1e20)
    while ll+1!=rr:
        mid=(ll+rr)//2
        if check(mid,t):
            ll=mid
        else:
            rr=mid  
    tot=ll
    while d[x]:
        if tot>r:
            tot-=r
            res[d[x].pop()]=r
        else:
            res[d[x].pop()]=tot
            break
    tot=ll
    while d[x]:
        if tot>abs(l):
            tot-=abs(l)
            res[d[x].pop()]=l
        else:
            res[d[x].pop()]=-tot
            break
print(*res[1:])