Remove Duplicates from Sorted Array II@leetcode

刷题必备书籍：Cracking the Coding Interview: 150 Programming Questions and Solutions 

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算法学习书籍：Introduction to Algorithms
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C++ 学习：The C++ Programming Language, 4th Edition
经典操作系统书籍，龙书：Operating System Concepts
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Follow up for "Remove Duplicates":
What if duplicates are allowed at most twice?

For example,
Given sorted array A = [1,1,1,2,2,3],

Your function should return length = 5, and A is now [1,1,2,2,3].

» Solve this problem

此题的基本思路还是和remove duplicates from sorted array一样，就是双指针，i and j，i 指向当前已经去掉了duplicate的subarray，j就一直往后搜寻，一直遇到和i指向的不同的，就做A[++i]=A[j].

此题多设了一个counter来看是否是两个了，有一些细节需要注意，但总体不难。看代码可知。

	class Solution {
	public:
	int removeDuplicates(int A[], int n) {
	// Start typing your C/C++ solution below
	// DO NOT write int main() function
	if(n<=1) return n;
	int count=0, i=0;
	for(int j=1; j<n; j++)
	{
	if(A[i]==A[j]&&count<2)
	{
	count=2;
	A[++i]=A[j];
	}
	else if(A[i]!=A[j])
	{
	A[++i]=A[j];
	count=0;
	}
	else if(count==2&&A[i]==A[j])
	continue;
	}
	return i+1;
	}
	};

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