leetcode -- Remove Duplicates from Sorted Array -- 简单重点

https://leetcode.com/problems/remove-duplicates-from-sorted-array/

思路简单。但是要找对循环点。removeDuplicates2中用j scan所有元素才是最佳方案。 ref: http://www.cnblogs.com/zuoyuan/p/3779816.html

class Solution(object):

    def removeDuplicates2(self, nums):
        if len(nums) == 0:
            return 0
        i = 0
        for j in range(0, len(nums)):# let j scan all the elements
            if nums[j] != nums[i]:
                nums[j], nums[i+1] = nums[i+1], nums[j]
                i += 1
        return i+1

    def removeDuplicates(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        if len(nums) == 0:
            return 0
        if len(nums) == 1:
            return 1

        i,j = 0,0
        while j < len(nums):# j == len(nums) is the stop condition

            while j < len(nums) and nums[j] == nums[i]:
                j += 1

            if j < len(nums):
                nums[i+1] = nums[j]
                i += 1

        return len(nums[:i + 1])