python C++速解Leetcode 1347 Minimum Number of Steps to Make Two Strings A...

python cpp速解Leetcode 1347  Minimum Number of Steps to Make Two Strings Anagram

No need for hash table. there are are just 26 alphabets.

s is anagram of t  ⟺ freq(s)==freq(t)

In other words, s is a permutation of t.

Python C++解二元搜尋樹問題Leetcode 938 Range Sum of BST

Python C++解二元搜尋樹問題Leetcode 938  Range Sum of BST。其實這是蠻典型二元收尋樹的問題，可以試著使用preorder, postorder & inorder等不同走訪的方式來解，二元收尋樹是資料結構的內容，會用它來寫程式跟不會用，就有顯著的區隔。