小黑忍着智齿疼痛写中期报告，不想返校的leetcode之旅:27. 移除元素

小黑代码

class Solution(object):
    def removeElement(self, nums, val):
        """
        :type nums: List[int]
        :type val: int
        :rtype: int
        """
        slow = 0
        n = len(nums)
        for fast in range(n):
            if nums[fast] != val:
                nums[slow] = nums[fast]
                slow += 1
        return slow 
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双指针优化(元素顺序改变,前后夹击看你黑驴往哪里逃!!!)

class Solution(object):
    def removeElement(self, nums, val):
        """
        :type nums: List[int]
        :type val: int
        :rtype: int
        """
        n = len(nums)
        before = 0
        after = n - 1
        while before <= after:
            if nums[before] != val:
                before += 1
            else:
                nums[before] = nums[after]
                after -= 1
        return before
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双指针优化（java版本）

class Solution {
    public int removeElement(int[] nums, int val) {
        int before = 0;
        int after = nums.length - 1;
        while(before<=after){
            if(nums[before] != val){
                before++;
            }else{
                nums[before] = nums[after];
                after--;
            }
        }
        return before;
    }
}
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小黑生活