打满鸡血来刷题

Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules.

The Sudoku board could be partially filled, where empty cells are filled with the character '.'.

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.

Implement strStr().

Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.

Given a linked list, swap every two adjacent nodes and return its head.

For example,
Given 1->2->3->4, you should return the list as 2->1->4->3.

Given a string containing just the characters (), [], {}, determine if the input string is valid.

The brackets must close in the correct order.

Given a linked list, remove the nth node from the end of list and return its head. Given n will always be valid and try to do this in one pass.

For example,

1
2
3

Given linked list: 1->2->3->4->5, and n = 2.
After removing the second node from the end, the linked list becomes 1->2->3->5.

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

Determine whether an integer is a palindrome. Do this without extra space.

Implement atoi to convert a string to an integer.

Reverse digits of an integer.

Example1: x = 123, return 321
Example2: x = -123, return -321