【哈希】49.字母异位词分组

力扣

Python

注意：一些基本语法需要掌握！！！

class Solution:
    def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
        resDict = {}
        for tmpStr in strs:
            key = ''.join(sorted(tmpStr)) # sorted(tmpStr) 相当于直接对str按照字符排序
            if key in resDict:
                resDict[key].append(tmpStr)
            else:
                resDict[key] = [tmpStr]   # list([tmpStr])也可
        
        return list(resDict.values())     # 外层必须加list()

Java

class Solution {
    public List<List<String>> groupAnagrams(String[] strs) {
        Map<String, List<String>> map = new HashMap<>();
        for (String str : strs) {
            String hash = getHash(str);
            map.computeIfAbsent(hash, k -> new ArrayList<>()).add(str);
        }

        return new ArrayList<>(map.values());
    }

    public String getHash(String str) {
        char[] array = str.toCharArray();
        Arrays.sort(array);
        return String.valueOf(array);
    }
}