187. Repeated DNA Sequences
Posted Machelsky
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了187. Repeated DNA Sequences相关的知识,希望对你有一定的参考价值。
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.
For example,
Given s = "AAAAACCCCCAAAAACCCCCCAAAAAGGGTTT", Return: ["AAAAACCCCC", "CCCCCAAAAA"].
比较经典的题目
思路:用hashmap扫一遍,出现过的就加到list上去,为了不使结果重复,当碰到重复的时候更新value。
public class Solution { public List<String> findRepeatedDnaSequences(String s) { List<String> res=new ArrayList<>(); if(s==null)return res; Map<String,Integer> check=new HashMap<>(); for(int i=0;i<=s.length()-10;i++){ String sub=s.substring(i,i+10); if(!check.containsKey(sub)){ check.put(sub,1); }else{ if(check.get(sub)==1){ res.add(sub); check.put(sub,2); } } } return res; } }
以上是关于187. Repeated DNA Sequences的主要内容,如果未能解决你的问题,请参考以下文章