String Manipulation

Question 1

trie tree

Answer 1

operations: insert a word, search a word, has word startsWith certain prefix

TrieNode can have multiple children, save children as a dictionary

stop word

Question 2

minimum substring containing all the characters in the target string

Answer 2

sliding window:

1. move end until a valid substring is found
2. move start until it’s the last position making it still valid
3. save the valid substring length (and start and end position)
4. move start by 1 (no longer valid)
5. go back to step 1