本文实例讲述了Python实现删除排序数组中重复项的两种方法。分享给大家供大家参考,具体如下:
对于给定的有序数组nums,移除数组中存在的重复数字,确保每个数字只出现一次并返回新数组的长度
注意:不能为新数组申请额外的空间,只允许申请O(1)的额外空间修改输入数组
Example 1:
Given 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
Example 2:
Given nums = [0,0,1,1,1,2,2,3,3,4],Your function should return length = 5, with the first five elements of nums being modified to 0, 1, 2, 3, and 4 respectively.
It doesn't matter what values are set beyond the returned length.
说明:为什么返回列表长度而不用返回列表?因为列表传入函数是以引用的方式传递的,函数中对列表进行的修改会被保留。
// nums is passed in by reference. (i.e., without making a copy) int len = removeDuplicates(nums); // any modification to nums in your function would be known by the caller. // using the length returned by your function, it prints the first len elements. for (int i = 0; i < len; i++) { print(nums[i]); }
1. 简单判断列表中元素是否相等,相等就删除多余元素
def removeDuplicates(self, nums): """ :type nums: List[int] :rtype: int """ if not nums: return 0 if len(nums)==1: #单独判断列表长度为1的情况,因为之后的for循环从下标1开始 return 1 temp_num = nums[0] count =0 #for循环中动态删除列表元素,列表缩短,为了防止下标溢出需要用count标记删除元素个数 for index, num in enumerate(nums[1:]): if temp_num == num: #元素相等就删除 del nums[index-count] count += 1 else: temp_num = num return len(nums) def removeDuplicates(self, nums): """ :type nums: List[int] :rtype: int """ forth = 0 back = 1 while back <= len(nums)-1: if nums[forth] == nums[back]: nums.pop(back) else: forth += 1 back += 1 return len(nums)
2. 修改数组,保证数组的前几个数字互不相同,且这几个数字的长度同返回长度相等
def removeDuplicates(self, nums): """ :type nums: List[int] :rtype: int """ if not nums: return 0 length = 0 #不存在重复数字的数组长度 for index in range(1,len(nums)): #遍历数组 if nums[index] != nums[length]: length += 1 nums[length] = nums[index] return length+1
算法题来自:https://leetcode-cn.com/problems/remove-duplicates-from-sorted-array/description/
PS:本站还有两款比较简单实用的在线文本去重复工具,推荐给大家使用:
在线去除重复项工具:
http://tools.jb51.net/code/quchong
在线文本去重复工具:
http://tools.jb51.net/aideddesign/txt_quchong
更多关于Python相关内容可查看本站专题:《Python字典操作技巧汇总》、《Python字符串操作技巧汇总》、《Python常用遍历技巧总结》、《Python数据结构与算法教程》、《Python函数使用技巧总结》及《Python入门与进阶经典教程》
希望本文所述对大家Python程序设计有所帮助。