虽丑但有用，python版的递归层数超了改成c++就行了（c++没存 def dfs(i): if i>n:return 0, 0, None isB = (cl[i-1] == 'B') cur_both = False lack = 'R' if isB else 'B' cur_res = 0 for j in ed[i]: ch_both, ch_res, lack = dfs(j) if ch_both or lack == cl[i-1]: cur_both = True lack = None cur_res += ch_res if cur_both: cur_res+=1 return cur_both, cur_res, lack print(dfs(1)[1])