LeetCode

Question 1

p283. Move Zeroes (3)

Answer 1

See solution.

Question 2

p344. Reverse String (1)

Answer 2

See last solution.

Question 3

p104. Maximum Depth of Binary Tree (1)

Answer 3

Solution: DFS
Parameters: n = a tree node.
1. if n is null, return 0.
2. return the 1 + the max of f(n.left) and f(n.right)

Question 4

p237. Delete Node in a Linked List (1)

Answer 4

See solution.

Question 5

p136. Single Number (4)

Answer 5

See solutions.

Question 6

p206. Reverse Linked List (1)

Answer 6

See first solution.

Question 7

p108. Convert Sorted Array to Binary Search Tree (1)

Answer 7

Solution: Recursion
Parameters: nums = a sorted list of numbers.
1. if nums is empty, return null.
2. m = the middle element of nums.
3. return a new node n
   a. n.value = m
   b. n.left = f(nums left of m)
   c. n.right = f(nums right of m)

Question 8

p169. Majority Element (5)

Answer 8

See all solutions except #4.

Question 9

p242. Valid Anagram (2)

Answer 9

See solutions.

Question 10

p122. Best Time to Buy and Sell Stock II (1)

Answer 10

See solution 3.