2085. 统计出现过一次的公共字符串

2085. 统计出现过一次的公共字符串

• 难度: easy
• 原始链接: https://leetcode.cn/problems/count-common-words-with-one-occurrence
• 标签: 哈希

解法一: 双哈希

go

func countWords(words1 []string, words2 []string) int {
    hash1 := make(map[string]int, len(words1))
    hash2 := make(map[string]int, len(words2))
    for _, word := range words1 {
        hash1[word]++
    }
    for _, word := range words2 {
        hash2[word]++
    }
    ans := 0
    for word, count := range hash1 {
        if count == 1 && hash2[word] == 1 {
            ans++
        }
    }
    return ans
}

解法二: 单哈希

go

func countWords(words1 []string, words2 []string) int {
    hash := make(map[string]int, len(words1))
    for _, word := range words1 {
        hash[word]++
    }
    ans := 0
    for _, word := range words2 {
        if count, exists := hash[word]; exists {
            if count == 1 {
                ans++
                hash[word] = -1
            } else if count == -1 {
                ans--
                delete(hash, word)
            }
        }
    }
    return ans
}