2024-09-09 Leetcode刷题

First Question

快慢指针

class Solution:def removeDuplicates(self, nums: List[int]) -> int:slow,fast = 0,1while fast < len(nums):if nums[fast] == nums[slow]:fast+=1;else:nums[slow+1] = nums[fast]fast += 1slow += 1return slow+1

Second Question

利用指针进行计数，后通过所计的数可以很方便的找到要替换的准确的位置

class Solution:def moveZeroes(self, nums: List[int]) -> None:offset = 0for i in range(len(nums)):if nums[i] == 0:offset += 1elif nums[i] != 0 and offset > 0:nums[i-offset] = nums[i]nums[i] = 0

Third Question

要记录的是连续1，所以要在计数该断的时候断（即遇到不是1的时候）

class Solution:def findMaxConsecutiveOnes(self, nums: List[int]) -> int:max,count = 0,0for i in range(len(nums)):if nums[i] == 1:count += 1else:count = 0if count > max:max = countreturn max

Fourth Question

题目只要求前K歌元素包含不等于val的元素，所以只需要把不是val的元素全部放在数组前面，并记录元素个数即可

class Solution:def removeElement(self, nums: List[int], val: int) -> int:i = 0;for x in nums:if x != val:nums[i] = xi+=1return i