Given an array of strings, group anagrams together.
Example:
Input: ["eat", "tea", "tan", "ate", "nat", "bat"] ,
Output:
[
["ate","eat","tea"],
["nat","tan"],
["bat"]
]
Note:
- All inputs will be in lowercase.
- The order of your output does not matter.
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Arrays;
class num49{
public static void main(String[] args) {
String[] strs = {"eat", "tea", "tan", "ate", "nat", "bat"};
List<List<String>> list = num49.groupAnagrams(strs);
for(List strlist:list){
for(Object s:strlist){
System.out.print(s+" ");
}
System.out.println('\n');
}
}
// 對每一個字元串進行排序的方法
public static List<List<String>> groupAnagrams1(String[] strs) {
Map<String,List<String>> map = new HashMap<String,List<String>>();
for(int i=0; i<strs.length; i++){
char[] ca = strs[i].toCharArray();
Arrays.sort(ca);
String key = String.valueOf(ca);
if(!map.containsKey(key)){
map.put(key, new ArrayList<>());
}
map.get(key).add(strs[i]);
}
return new ArrayList(map.values());
}
// 使用字元數組的方法
public static List<List<String>> groupAnagrams2(String[] strs) {
Map<String, List<String>> map = new HashMap<String, List<String>>();
for(String str: strs){
int[] count = new int[26];
for(int i=0; i<str.length(); i++){
count[str.charAt(i) - 'a'] += 1;
}
String key = Arrays.toString(count);
if(!map.containsKey(key)){
List<String> list = new ArrayList<>();
list.add(str);
map.put(key, list);
}else{
map.get(key).add(str);
}
}
return new ArrayList(map.values());
}
}