【10】Regular Expression Matching
【17】Letter Combinations of a Phone Number
【22】Generate Parentheses
【37】Sudoku Solver
【39】Combination Sum
【40】Combination Sum II
【44】Wildcard Matching
【46】Permutations
【47】Permutations II
【51】N-Queens
【52】N-Queens II
【60】Permutation Sequence
【77】Combinations
【78】Subsets
【79】Word Search
【89】Gray Code
【90】Subsets II
【93】Restore IP Addresses
【126】Word Ladder II
【131】Palindrome Partitioning
【140】Word Break II
【211】Add and Search Word - Data structure design
【212】Word Search II
【216】Combination Sum III
【254】Factor Combinations
【267】Palindrome Permutation II
【291】Word Pattern II
【294】Flip Game II
【306】Additive Number
【320】Generalized Abbreviation
【351】Android Unlock Patterns
【357】Count Numbers with Unique Digits
【401】Binary Watch
【411】Minimum Unique Word Abbreviation
【425】Word Squares
【526】Beautiful Arrangement
【691】Stickers to Spell Word
【784】Letter Case Permutation
【842】Split Array into Fibonacci Sequence
【LeetCode】回溯法 backtracking（共39题）
原文：https://www.cnblogs.com/zhangwanying/p/9886305.html