leetcode：Remove Duplicates from Sorted Array（去掉数组重复数字，常数空间限制）【面试算法题】
题目：
Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.
Do not allocate extra space for another array, you must do this in place with constant memory.
For example,
Given input array A = [1,1,2],
Your function should return length = 2, and A is now [1,2].
题意去掉数组重复的数字，并返回不同数字的个数，常数空间限制。
用num存不同数字的个数，遍历数组，判断当前值是否和前一个值不一样。
如果不一样，就是一个新的值，更新数组并对num加一。
class Solution {public: int removeDuplicates(int A[], int n) { if(!n)return NULL; int num=1,i; for(i=1;i<n;++i) if(A[i]!=A[i-1]) A[num++]=A[i]; return num; }};// blog.csdn.net/havenoidea