187. Repeated DNA Sequences
All DNA is composed of a series of nucleotides abbreviated as A, C, G, and T, for example: "ACGAATTCCG". When studying DNA, it is sometimes useful to identify repeated sequences within the DNA.
Write a function to find all the 10-letter-long sequences (substrings) that occur more than once in a DNA molecule.
思路：
题目意思是找出重复的序列，采用滑动窗口和hashset不可以重复的特性来做。
代码：
java：
代码语言：javascript复制class Solution {
public List<String> findRepeatedDnaSequences(String s) {
Set curr = new HashSet(), repeated = new HashSet();
for (int i = 0; i 9 < s.length(); i ) {
String ten = s.substring(i, i 10);
if (!curr.add(ten))
repeated.add(ten);
}
return new ArrayList(repeated);
}
}
