题目

Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

**Example 1:**

**Input:** 121
**Output:** true

**Example 2:**

**Input:** -121
**Output:** false
**Explanation:** From left to right, it reads -121\. From right to left, it becomes 121-. Therefore it is not a palindrome.

**Example 3:**

**Input:** 10
**Output:** false
**Explanation:** Reads 01 from right to left. Therefore it is not a palindrome.

**Follow up:**

Coud you solve it without converting the integer to a string?

题目

Two Sum

Given an array of integers, return **indices** of the two numbers such that they add up to a specific target.

You may assume that each input would have **_exactly_** one solution, and you may not use the _same_ element twice.

Example:

Given nums = [2, 7, 11, 15], target = 9,

Because nums[**0**] + nums[**1**] = 2 + 7 = 9,
return [**0**, **1**].

题目

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.

Example:

Input: 1->2->4, 1->3->4
Output: 1->1->2->3->4->4