How to switch against odd and even number ?

Question

input : 4
output : 2 1 4 3
input : 7
output : 2 1 4 3 6 5 8
please help me again 🙏

Answer 1

Post your code. More than happy to help you.

Answer 2

https://code.sololearn.com/ccNerJxN3H91/?ref=app