LeetCode [187] Repeated DNA Sequences

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Note

• method1: use unordered_map
• 'A' - 64 = 1 (mod 5) = 1 'C' - 64 = 3 (mod 5) = 3 'G' - 64 = 7 (mod 5) = 2 'T' - 64 = 20 (mod 5) = 0
• OJ does have test cases in which the given string is less than 9
• method2: use an array

Ref
[1] https://oj.leetcode.com/problems/repeated-dna-sequences/
OJ
[2] https://oj.leetcode.com/discuss/24478/i-did-it-in-10-lines-of-c
method1