private int add(int input, char ch) {
        int val = getVal(ch);
        input = input<<2;
        input = input & mask;
        return input | val;
    }
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