A second example, a call like this searchInLastN $($nums$,2,7)$ would check positions $[8]$ and $[9]$ and return $-1($not found$)$ as the value $7$ is not in the last $2$ positions.

$1$ searchInLastw$($nums$,2,7)-1$

This should work for arrays of any size. You can assume that the array size is larger than the value in lastN.

Examples:

searchInLastN $(\{9,18,3,17,12,10,7,5,3,15\},3,5)7$

searchInLastN $(\{9,18,3,17,12,10,7,5,3,15\},2,7)-1$

searchInLastN $(\{9,18,3,17,12,10,7,5,3,15\},10,9)0$

searchInLastN $(\{9,18,3,17,12,10,7,5,3,15\},10,3)2$