leetcode:26&80 Remove Duplicates from Sorted Array 删除数组中的重复元素

leetcode:26

class Solution(object):
def removeDuplicates(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
if len(nums) == 0:
return 0
k = 0
for i in range(1, len(nums)):
if nums[k] != nums[i]:
k += 1
nums[k] = nums[i]
return k + 1

class Solution2(object):
def removeDuplicates(self, nums):
"""
利用python属性
:type nums: List[int]
:rtype: int
"""
nums[:] = sorted(set(nums))
return len(nums)

leetcode 80

class Solution(object):
"""
对数组元素进行去重，使得原数组重复元素最多保留2个
"""
def removeDuplicates(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
if len(nums) <= 2:
return len(nums)

i, j, cnt = 1, 1, 1
while j < len(nums):
if nums[j] != nums[j - 1]:
cnt = 1
nums[i] = nums[j]
i += 1
else:
if cnt < 2:
nums[i] = nums[j]
i += 1
cnt += 1
j += 1
return i

def removeDuplicates2(self, nums):
"""
very short code
:param nums:
:return:
"""
i = 0
for n in nums:
if i < 2 or n > nums[i - 2]:
nums[i] = n
i += 1
return i

问题来了：如果使得原数组重复元素最多保留k个

class Solution1(object):
"""
对数组元素进行去重，使得原数组重复元素最多保留k个
"""
def removeDuplicates(self, nums, k):
"""
:type nums: List[int]
:rtype: int
"""
if len(nums) <= k:
return len(nums)

i, j, cnt = 1, 1, 1
while j < len(nums):
if nums[j] != nums[j - 1]:
cnt = 1
nums[i] = nums[j]
i += 1
else:
if cnt < k:
nums[i] = nums[j]
i += 1
cnt += 1
j += 1
return i

def removeDuplicates2(self, nums, k):
"""
very short code
:param nums:
:return:
"""
i = 0
for n in nums:
if i < k or n > nums[i - k]:
nums[i] = n
i += 1
return i