标签：leetcode
题意：题目意思很简单就是有一个由 A C G T 组成的字符串，要求找出字符窜中出现次数不止1次的字串 public List<String> findRepeatedDnaSequences(String s) {
List<String> rs = new LinkedList<String>();
Map<String, Integer> map = new HashMap<String, Integer>();
for(int i =0; i <= s.length() - 10; ++i){
String substr = s.substring(i, i + 10);
if(map.containsKey(substr)){
map.put(substr,map.get(substr) + 1);
}else {
map.put(substr, 1);
}
}
for(Map.Entry<String, Integer> en : map.entrySet()){
if(en.getValue() > 1){
rs.add(en.getKey());
}
}
return rs;
} /**
* 将字符转换成二进制编码
* @param s
* @return
*/
public List<String> findRepeatedDnaSequences(String s){
List<String> rs = new LinkedList<String>();
if(s.length() < 10) return rs;
Map<Character, Integer> c2i = new HashMap<Character, Integer>();
c2i.put('A', 1);
c2i.put('C', 2);
c2i.put('G', 3);
c2i.put('T', 4);
Map<Integer, Integer> res = new HashMap<Integer, Integer>();
Set<Integer> added = new HashSet<Integer>();
int target = 0;
for(int i = 0; i < s.length(); i ++){
if(i < 9){
target = (target << 2) + c2i.get(s.charAt(i));
}else {
target = (target << 2) + c2i.get(s.charAt(i));
target = target & ((1 << 20) -1);//保证是二十位
if(res.containsKey(target) && !added.contains(target)){
rs.add(s.substring(i - 9, i + 1));
added.add(target);
}else {
res.put(target, 1);
}
}
}
return rs;
}[LeetCode]Repeated DNA Sequences Total
标签：leetcode
原文地址：http://blog.csdn.net/youmengjiuzhuiba/article/details/45768605
