884. Uncommon Words from Two Sentences #

Problem #

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.

Problem Summary #

Given two sentences A and B. (A sentence is a string of words separated by spaces. Each word consists only of lowercase letters.)

If a word appears exactly once in one sentence and does not appear in the other sentence, then this word is uncommon. Return a list of all uncommon words. You may return the list in any order.

Solution Approach #

• Find the different words in the 2 sentences and print both of them. This is an easy problem. First split the words from both sentences and put them into a map to count word frequencies. The frequencies of the two different words must both be 1, so just output them.

Code #

package leetcode

import "strings"

func uncommonFromSentences(A string, B string) []string {
	m, res := map[string]int{}, []string{}
	for _, s := range []string{A, B} {
		for _, word := range strings.Split(s, " ") {
			m[word]++
		}
	}
	for key := range m {
		if m[key] == 1 {
			res = append(res, key)
		}
	}
	return res
}