49. Group Anagrams

QUESTION:

Given an array of strings strs, group the anagrams together. You can return the answer in any order.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

Example 1:

Input: strs = ["eat","tea","tan","ate","nat","bat"]
Output: [["bat"],["nat","tan"],["ate","eat","tea"]]

Example 2:

Input: strs = [""]
Output: [[""]]

Example 3:

Input: strs = ["a"]
Output: [["a"]]

Constraints:

1 <= strs.length <= 104
0 <= strs[i].length <= 100
strs[i] consists of lowercase English letters.

EXPLANATION:

思路肯定就是, 首先将单个str进行排序, 再把排序结果当成key, 然后把对应的坐标当成value,进行保存, 这样就相当于对strs进行了排序. 最后再将排序后的dic展开成最后的结果即可.

SOLUTION:

class Solution {
    func groupAnagrams(_ strs: [String]) -> [[String]] {
        var dic: Dictionary<String, [Int]> = [:]
        for (i, str) in strs.enumerated() {
            dic[String(str.sorted()), default: []].append(i)
        }
        var result: [[String]] = []
        for value in dic.values {
            var tmpArr: [String] = []
            for v in value {
                tmpArr.append(strs[v])
            }
            result.append(tmpArr)
        }
        return result
    }
}
--> return <--