CONY的世界

 69. Sqrt(x)

Implement int sqrt(int x).
Compute and return the square root of x.
x is guaranteed to be a non-negative integer.


Example 1:
Input: 4
Output: 2

 
Example 2:
Input: 8
Output: 2
Explanation: The square root of 8 is 2.82842..., and since we want to return an integer, the decimal part will be truncated.

 
 這題我只想到暴力解，所以就直接放棄看解答了，解法非常有趣
用BFS，不斷逼近正確的區段，因為有可能不是整數，最後確定數值是用 if(mid+1 > x/(mid+1)) 來判斷  （來確定下個值會過大，正解就是這個值）

88. Merge Sorted Array
Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.

 234. Palindrome Linked List
Given a singly linked list, determine if it is a palindrome.
Follow up:
Could you do it in O(n) time and O(1) space?

283. Move Zeroes  
Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements.

13. Roman to Integer

Given a roman numeral, convert it to an integer.
Input is guaranteed to be within the range from 1 to 3999.