LeetCode OJ_题解（python）:026-Remove Duplicates from Sorted Array 【Array】【Easy】

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 nums = [1,1,2],

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

 

给定一个排好序的数组，去除重复的数，返回新数组的长度，不能申请额外的空间，超过新数组长度部分是什么数都无所谓。

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题目思路：

    由于给定的数组已经排序，那么用i，j两个下标，i记录新数组的下标，j是原来数组下标，如果nums[j] != nums[i - 1]，那么nums[i] = nums[j]，i 和j 都+ 1。最后返回i。

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代码：

class Solution(object):
    def removeDuplicates(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        i = 0
        j = 1
        size = len(nums)
        while j <size:    #  保证循环结束
            if nums[j] == nums[i]:     #  若有重复的数
                j += 1
            else:
                nums[i] = nums[j]      #  将在比较的数赋给下一个数
                i += 1
                j += 1
        return i + 1
if __name__ == "__main__":
    s = Solution()
    print(s.removeDuplicates(nums =[1, 1, 2]))