# LeetCode 70. Climbing Stairs

Description https://leetcode.com/problems/climbing-stairs/ You are climbing a stair case. It takes n steps to reach to the top. Each time you can either…

# LeetCode 387. First Unique Character in a String

Description https://leetcode.com/problems/first-unique-character-in-a-string/description/ Given a string, find the first non-repeating character in it and return it’s index. If it doesn’t exist,…

# LeetCode 26. Remove Duplicates from Sorted Array

Description https://leetcode.com/problems/remove-duplicates-from-sorted-array/description/ Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length. Do not…

# LeetCode 102. Binary Tree Level Order Traversal

Description https://leetcode.com/problems/binary-tree-level-order-traversal/description/ Given a binary tree, return the level order traversal of its nodes’ values. (ie, from left to right, level by…

# LeetCode 101. Symmetric Tree

Description https://leetcode.com/problems/symmetric-tree/description/ Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For…