https://blog.csdn.net/Lynn_Baby/article/details/80790796
题目描述:
Given an array of strings, return all groups of strings that are anagrams.
Note: All inputs will be in lower-case.
思路解析:
1.首先判空
2.创建元素类型为ArrayList(String)的ArrayList作为结果res,创建元素类型为(String,ArrayList(String))的HashMap
3.遍历strs,把每个字符串Arrays.sort以后,再分组存入HashMap
4.遍历HashMap的values,存入res,返回res
代码:
public static void main(String[] args) throws IOException {
String[] strs = {"a","acb","bca","aabcd","abcdefgh","abdca"};
ArrayList<ArrayList<String>> res = anagrams(strs);
System.out.println(res);
//[[acb, bca], [aabcd, abdca], [a], [abcdefgh]]
}
//按照单词的字母是否相同对字符串数组进行分组
public static ArrayList<ArrayList<String>> anagrams(String[] strs) {
ArrayList<ArrayList<String>> res = new ArrayList<ArrayList<String>>();
if(strs==null || strs.length==0){
return res;
}
HashMap<String,ArrayList<String>> hm = new HashMap<String,ArrayList<String>>();
for(String s : strs){
char[] ch = s.toCharArray();
Arrays.sort(ch);
String temp = new String(ch);
if(hm.containsKey(temp)){
hm.get(temp).add(s);
hm.put(temp, hm.get(temp));
}else{
ArrayList<String> templist = new ArrayList<String>();
templist.add(s);
hm.put(temp,templist);
}
}
Collection<ArrayList<String>> values=hm.values();
for(Iterator it=values.iterator();it.hasNext();){
res.add((ArrayList<String>)it.next());
}
return res;
}