leetcode之Remove Duplicates from Sorted Array

从排好序的列表中删除重复数。这个有Counter之后就可以反过来先算出来哪些重复，该删多少个，然后删就是了。代码如下：

class Solution(object):
    def removeDuplicates(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        from collections import Counter
        a = Counter(nums)        
        for i in a.keys():
            if a[i] > 1:             
                for j in range(a[i] - 1):
                    nums.remove(i)        
        return len(nums)

好点的方法就是跟分类讲的那种了。

class Solution(object):
    def removeDuplicates(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        if nums == []:
            return 0
        if len(nums) == 1:
            return 1
        prev = nums[0]
        p = 1
        for i in range(len(nums) - 1):
            if prev == nums[i + 1]:
                continue
            nums[p] = nums[i + 1]
            p = p + 1
            prev = nums[i + 1]
        return p