private char getChar(int val) {
        switch (val) {
            case 0:
                return 'A';
            case 1:
                return 'C';
            case 2:
                return 'G';
            case 3:
                return 'T';
            default:
                throw new IllegalArgumentException();
        }
    }
Date 03/08/2016
@author Tushar Roy

Find repeated sequence of length 10 in string consisting of A,C,G,T

Time complexity is O(n)
Space complexity is O(n)

https://leetcode.com/problems/repeated-dna-sequences/
src/com/interview/bits/RepeatedDnaSequence.java