Question$3(10$ points$)$

Assume that two servers are communicating with each other in a ciphered language via string streams; that is$,$ the messages are sent through without interruption. They utilize a specified sequence pattern to identify the position of the message start. This pattern is $BDDD,$ and your task is to find the location of this pattern in the given string patch. Your function takes a string patch and outputs the first location of the pattern that occurred in the patch. Note that indices start from $0$ for strings.

Contract

contract: findLocation: patch$($string$)$ number

Examples

$($check$-$expect $($findLocation "CDCBBDDDBCABCC"$)4)$

$($check$-$expect $($findLocation "ADDDAACBDDDDCAACD"$)7)$

$($check$-$expect $($findLocation "CAABDDDBACAAA"$))$

U can only solve it with this list of available functions.