5.30 notes

Review:
101. symmetrical binary tree: the left and right sides of a binary tree can be divided into two binary trees, there is an equal relationship determining a recursive tree left and another tree.
105. Construction of binary tree according to the preamble and in order: to find the root according to the preamble, in order to find the current root index, 0-index left subtree, index: is the right subtree, layer by layer recursion.
106. The order and the subsequent build: the preamble is substantially the same, except the root node is the last sequence.
171.Excel tabulated ID: read from back to front the STR:
RES = RES + (the ord (I) -ORd ( 'A') +. 1) p *
p * = 26 is
returned res, wherein p is initialized to 1, res 0. initialization
will be zero when only digital multiplication factor of 5: 172.0 after factorial. Then in the range of 1-n are multiples of 5 will increase to zero. And where there is a need to note that some figures such as 25, 125 and so on which is more than a factor of 5, 5 there are several factors to add a few. I.e., derived specifically explained: https://www.cnblogs.com/hutonm/p/5624996.html