LeetCode----Remove Duplicates from Sorted Array-优快云博客

本文介绍了一种高效的方法来移除已排序数组中的重复元素，并确保每个元素只出现一次。通过使用双指针技术，在O(n)的时间复杂度和O(1)的空间复杂度下实现了这一目标。

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Remove Duplicates from Sorted Array

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.

分析：

从已排序的数组中“删除”重复的元素，要求O(1)的空间。简单题。

使用两个指针p,q，一个指针遍历数组，另一个指针纪录无重复元素的数组的下标。

Python代码：

class Solution(object):
    def removeDuplicates(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        nums_len = len(nums)
        if nums_len <= 1:
            return nums_len
        p, q = 1, 1
        while p < nums_len:
            if nums[p] != nums[p - 1]:
                nums[q] = nums[p]
                q += 1
            p += 1
        return q

C++代码：

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        int nums_len = nums.size();
        if(nums_len <= 1){
            return nums_len;
        }
        for(int p = 1, q = 1; p < nums_len; p++){
            if(nums[p] != nums[p - 1]){
                nums[q++] = nums[p];
            }
        }
        return q;
    }
};