Use this to refresh at tictime freq when no event is happening avoid frozen the TUI

check a *preOrder-list* s from left of its preOrderLst until forming a valid proposition return ('if s[begin:end]

This should be run only after weight of the first n nodes are decided (tree size 2*n-1)

Door closed, continue moving or stay still

also a func with recursive call, the func means things happened when elev door is opened, person get off and get on ONE BY ONE LOW TIME PERFORMANCE WA

This func is NOT GOOD ENOUGH, some small points NOT CONSIDIRED but it can work

Generate huffman code using a huffman tree

for i-th work

broad first search

:type equations: List[List[str]] :type values: List[float] :type queries: List[List[str]] :rtype: List[float]

check if this file should be added to the zip

when deleting a node which has two kids, copy its succesor's data to his position data exclude left, right , isBlack

when deleting a node which has two kids, copy its succesor's data to his position data exclude left, right , isBlack

注意!!!如果没有return 语句，返回int的函数默认返回非0值*/

delete node in a binary search tree

delete node in a binary search tree

mat: matrix of c_ij