1) Solve in Python.

a.

Given a string, consider the prefix string made of the first N chars of the string. Does that prefix string appear somewhere else in the string? Assume that the string is not empty and that N is in the range 1..str.length()1

def prefixAgain(str, n):

b.

Given a string, if the same 2-character substring appears at both its beginning and end, return the contents of the string without the 2-character substring at the beginning. For example, "HelloHe" yields "lloHe". Note that the 2-character substring at the beginning may overlap with the one at the end, so "Hi" yields "". If the two characters at the start and end of the string do not match each other, return the original string unchanged.

Examples:

without2("HelloHe") -> "lloHe" without2("HelloHi") -> "HelloHi" without2("Hi") -> ""

def without2(str):