Swap Consecutive Even Elements in Python

Suppose we have a list of numbers called nums, we have to exchange every consecutive even integer with each other.

So, if the input is like nums = [4, 5, 6, 8, 10], then the output will be [6, 5, 4, 10, 8]

To solve this, we will follow these steps −

• temp := null
• for i in range 0 to size of nums, do
  • if nums[i] mod 2 is same as 0, then
    • if temp is not null, then
      • exchange nums[i], nums[temp]
      • temp := null
    • otherwise,
      • temp := i
• return nums

Let us see the following implementation to get better understanding −

Example

class Solution:
   def solve(self, nums):
      temp = None
      for i in range(len(nums)):
         if nums[i] % 2 == 0:
            if temp is not None:
               nums[i], nums[temp] = nums[temp], nums[i]
               temp = None
            else:
               temp = i
      return nums
ob = Solution()
print(ob.solve([4, 5, 6, 8, 10]))

Input

[4, 5, 6, 8, 10]

Output

[6, 5, 4, 10, 8]