题目

Follow up for "Remove Duplicates":
What if duplicates are allowed at most twice?

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

Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3. It doesn't matter what you leave beyond the new length.

分析

从已排序数组中去除重复数字，但最多可以重复两次。利用上一题的思路：http://www.jianshu.com/p/2ea74e4e2f4c
就是需要判断两次，先判断和前个是否相同，之后判断再前面一个是否相同。

int removeDuplicates(int* nums, int numsSize) {
    int length=1;
    if(numsSize==0||numsSize==1)return numsSize;
    if(nums[0]==nums[1])length=2;
    for(int i=length;i<numsSize;i++)
    {
        if(nums[i]!=nums[length-1]||(nums[i]==nums[length-1]&&nums[i]!=nums[length-2]))
        {
            nums[length]=nums[i];
            length++;
        }
    }
    if(numsSize==0)return 0;
    else return length;
}