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。
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/ / 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]);
}
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1. 简单判断列表中元素是否相等,相等就删除多余元素
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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)
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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
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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
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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:https://tool.zzvips.com/t/quchong/
在线文本去重复工具:https://tool.zzvips.com/t/txtquchong/
希望本文所述对大家Python程序设计有所帮助。
原文链接:https://blog.csdn.net/qiubingcsdn/article/details/82142817