solutions

目录

Atoi 4

Valid Palindrome 5

addBinary 6

Longest Palindromic Substring 7

Regular Expression Matching 8

Valid Number 9

Count and say 9

Valid anagram 10

Simplify Path 10

Length of last word 11

Longest Valid Parentheses 11

Valid Parentheses 12

Largest Rectangle in Histogram 13

Evaluate Reverse Polish Notation 13

Morris 算法介绍 15

Binary Tree Preorder Traversal 16

//stack 16

//morris 16

Binary Tree Inorder Traversal 17

//stack 17

//morris 18

Binary Tree Postorder Traversal 19

//stack 19

Binary Tree Level Order Traversal 22

递归 22

迭代 23

Binary Tree Zigzag Level Order Traversal 24

递归 24

迭代 24

Recover Binary Search Tree 25

Recursive 25

morris 26

Same Tree 27

Symmetric Tree 28

Recursive 28

Iterative 29

Balanced Binary Tree 30

Flatten Binary Tree to Linked List 31

Iterative and recursive 31

Populating Next Right Pointers in Each Node II 32

Iterative 32

Recursive 32

Construct Binary Tree from Preorder and Inorder Traversal 33

Construct Binary Tree from Inorder and Postorder Traversal 34

Unique Binary Search Trees 34

Validate Binary Search Tree 35

Convert Sorted Array to Binary Search Tree 35

Convert Sorted List to Binary Search Tree 36

Minimum Depth of Binary Tree 37

Maximum Depth of Binary Tree 37

Path Sum 38

Path Sum II 38

Binary Tree Maximum Path Sum 39

Populating Next Right Pointers in Each Node 40

Sum Root to Leaf Numbers 40

Merge Sorted Array 41

Merge Two Sorted Lists 41

cpp 41

java 42

Merge k Sorted Lists 42

Priority queue 43

merge sort 44

Insertion Sort List 44

Sort List 45

First Missing Positive 45

Sort Colors 46

Search for a Range 46

Search Insert Position 47

Recursive 47

Iterative 48

Search a 2D Matrix 49

*string 的子集(bit) 49

Subsets 50

Bit 50

Recursive 50

Iterative 51

Subsets II 52

Recursive 52

Iterative 53

Permutations 54

Permutations II 55

Java 55

CPP 56

Combinations 57

Recursive 57

Iterative 59

Letter Combinations of a Phone Number 59

Recursive 59

BFS VS DFS 60

Word Ladder 61

Java 61