python

def search(nums, target: int) -> int:  
    result = -1  
    right = len(nums) - 1  
    left = 0  
    middle = int(right / 2)  
    while True:  
        if left == right:  
            if target == nums[middle]:  
                result = middle  
            break  
        if target == nums[middle]:  
            result = middle  
            break  
        elif target > nums[middle]:  
            left = middle + 1  
            middle = int((left + right) / 2)  
        elif target < nums[middle]:  
            if middle==left: # 处理边界条件，例如两个元素，为什右边不会有这个情况  
                right = middle  
            else:  
                right = middle - 1  
            middle = int((left + right) / 2)  
    return result  
  
if __name__ == '__main__':  
    print(search([2,3,4,5,6],7))

python

    def removeElement(self, nums: List[int], val: int) -> int:  
    '''
    双指针法
    '''
        f=0
        s=0

        while (f<=len(nums)-1):
            if nums[f]==val:
                f+=1
                continue
            else:
                nums[s]=nums[f]
                f+=1
                s+=1
        return len(nums[:s])

    def removeElement(self, nums: List[int], val: int) -> int:  
    ‘‘‘
    暴力移除
    '''
        i = 0
        while (i < len(nums)):
            if nums[i] == val:
                for j in range(i, len(nums) - 1):
                    nums[j] = nums[j + 1]
                del(nums[-1])
            else:
                i += 1
        return len(nums)