Yang Shuqi

Move Zeroes

 

    448. Move Zeroes

    Solution 1 - Swap

    1. If the num is not 0, move forward if possible, i.e. zero < i, nums[zero] = nums[i]

    2. If the num is 0, leave it and search for the number to ‘fill in’ it.

    3. The key point is zero < i because zero is not updated at each iteration.

    def moveZeroes(self, nums):
    """
    :type nums: List[int]
    :rtype: None Do not return anything, modify nums in-place instead.
    """

    zero = 0  # records the position of "0"
    for i in xrange(len(nums)):
        if nums[i] != 0:
            nums[i], nums[zero] = nums[zero], nums[i]
            zero += 1

    Solution 2 - Re-assign

    1. Get the index of all zeros.

    2. Copy the other numbers to the beginning of the array.

    3. Assign the last few positions 0 value.

    def moveZeroes(self, nums):
    """
    :type nums: List[int]
    :rtype: void Do not return anything, modify nums in-place instead.
    """
    count=nums.count(0)
    nums[:]=[i for i in nums if i != 0]
    nums+=[0]*count
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