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Valid Pairing of Numbers
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# Valid Pairing of Numbers

Contributed by
Dhruv Sharma
Hard
0/120
Avg time to solve 50 mins
Success Rate 50 %
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## Problem Statement

#### You are provided with a list of numbers from ‘0’ to (2 * ’N’ - 1). You have to find the minimum number of swaps needed to make every even number ‘E’ (present in the list) adjacent to (‘E’ + 1).

##### For Example:
``````List = [3, 0, 2, 1]

We have to make ‘0’ adjacent to ‘1’ and ‘2’ to ‘3’. And, to achieve this we can swap ‘0’ with ‘2’.

New list = [3, 2, 0, 1].

Therefore, the answer (minimum number of swaps) is equal to 1.
``````
##### Note:
``````There will be only distinct numbers present in the given list.
``````
Detailed explanation ( Input/output format, Notes, Constraints, Images )
##### Sample Input 1:
``````1
2
3 0 2 1
``````
##### Sample Output 1:
``````1
``````
##### Explanation of sample input 1:
``````For the first test case, an explanation is given in the description.
``````
##### Sample Input 2:
``````2
1
1 0
3
1 0 2 3 5 4
``````
##### Sample Output 2:
``````0
0
``````
##### Explanation for sample input 2:
``````In the first test case, the required pairing of all the even numbers is already done.

In the second test case, the required pairing of all the even numbers is already done.
``````
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