Given an array nums and a value val, remove all instances of that value in-place and return the new length.

Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length.

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.

年前嘛，就是各种涣散的状态。在拖完地板之后，想想还是补上今天的题解吧~感谢小佳扬推荐的题目，默默的复习了一把递归~

Given a string containing just the characters ‘(‘, ‘)’, ‘{‘, ‘}’, ‘[‘ and ‘]’, determine if the input string is valid.An input string is valid if:Open brackets must be closed by the same type of br…

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M.

Write a function to find the longest common prefix string amongst an array of strings.

TIME:2019-02-01昨晚其实刷了题来着，但是没有解出来，哭泣！但是，今天重新写了下，解出来咯~所以今天的题量要增加咯~我会加油的！

Given a non-empty 2D array grid of 0’s and 1’s, an island is a group of 1’s (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are sur…