Can anyone check if I missed any scenario ?

1, 2, 3, 4, 5 => Nothing to do here"
5, 4, 3, 2, 1 => Nothing to do here"
5, 2, 3, 4, 1 => "Yes\n1 5"
1, 8, 3, 4, 5, 6, 7, 2, 9 => "Yes\n2 8"
1, 8, 7, 6, 5, 4, 3, 2, 9 => "Yes\n1 9"
9, 8, 3, 6, 5, 4, 7, 2, 1 => "Yes\n3 7"
1 => Nothing to do here"
1, 1, 1, 1, 1 => "Nothing to do here"
9, 2, 3, 5, 4, 6, 7, 8, 1 => "No hope"
1, 2, 3, 9, 5, 6, 7 => "No hope"
7, 6, 5, 9, 3, 2, 1 => "No hope"
1, 1 => "Nothing to do here"
1, 2 => "Nothing to do here"
1, 2, 4, 3, 5, 6 => "Yes\n3 4"
6, 5, 3, 4, 2, 1 => "Yes\n3 4"
2, 1, 3 => "Yes\n1 2"
1, 3, 2 => "Yes\n2 3"
1, 2, 3, 2, 3, 4, 5 => "Yes\n3 4"
1, 5, 7, 2, 4, 5 => "No hope"

If there are repeated digits, make sure you switch the right one. For example:

5
2 1 1 1 3

Try to generate tests containing a lot of same numbers, e.g. the next test:
9
1 5 1 3 3 3 5 1 5
has answer:
Yes
2 8