Description

We are given two sentences A and B. (A sentence is a string of space separated words. Each word consists only of lowercase letters.)

A word is uncommon if it appears exactly once in one of the sentences, and does not appear in the other sentence.

Return a list of all uncommon words.

You may return the list in any order.

Example 1:

Input: A = "this apple is sweet", B = "this apple is sour"
Output: ["sweet","sour"]

Example 2:

Input: A = "apple apple", B = "banana"
Output: ["banana"]

Note:

  1. 0 <= A.length <= 200
  2. 0 <= B.length <= 200
  3. A and B both contain only spaces and lowercase letters.

分析

题目的意思是：给定两个句子，找出其中的uncommon的句子。这道题换句话说找出词频为1的单词，如果想到这个就很好了，我看标准解答直接用一个字典统计词频然后把词频为1的找出来就行了。

  • 我的解法有点中规中矩，用了两个字典，分别统计词频，然后取出词频为1的单词，相比于标准答案稍稍复杂了一点，哈哈哈。

代码

class Solution:
    def uncommonFromSentences(self, A: str, B: str) -> List[str]:
        dA=defaultdict(int)
        dB=defaultdict(int)
        arrA=A.split()
        arrB=B.split()
        for item in arrA:
            dA[item]+=1
        for item in arrB:
            dB[item]+=1
        res=[]
        for k,v in dA.items():
            if(v==1 and k not in dB):
                res.append(k)
        for k,v in dB.items():
            if(v==1 and k not in dA):
                res.append(k)
        return res

参考文献

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