pre, nex = 0, 0
        while pre < len(nums):
            if nums[pre] % 2 == 1:
                nums[pre], nums[nex] = nums[nex], nums[pre]
                nex += 1
            pre += 1
        return nums

''' 
        l, r = 0, len(nums) - 1
        while l < r:
            while l < r and nums[l] % 2 == 1:
                l += 1
            while l < r and nums[r] % 2 == 0:
                r -= 1
            nums[l], nums[r] = nums[r], nums[l]
        return nums
       
        l, r = 0, len(nums) - 1
        while l < r:
            if nums[l] % 2 == 1:
                l += 1
                continue
            elif nums[r] % 2 == 0:
                r -= 1
                continue
            
            nums[l], nums[r] = nums[r], nums[l]
        return nums