Determine if String Halves Are Alike

You are given a string s of even length. Split this string into two halves of equal lengths, and let a be the first half and b be the second half.

String to Integer (atoi)

Here we are going to write our own atoi() implementation in Java. Remember in Java you convert a string to an integer using the parseInt method of the Java Integer class. The parseInt method converts the String to an int, and throws a NumberFormatException if the string can’t be converted to an int type.

Isomorphic Strings

Given two strings s and t, determine if they are isomorphic. Two strings are isomorphic if the characters in s can be replaced to get t. All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character but a character may map to itself.