[LeetCode] 1002. Find Common Characters 查找共同字符

题目

1002. Find Common Characters

题意

Given an array A of strings made only from lowercase letters, return a list of all characters that show up in all strings within the list (including duplicates). For example, if a character occurs 3 times in all strings but not 4 times, you need to include that character three times in the final answer.

You may return the answer in any order.

思路

每个字符串都仅由26个小写字母组成。那么，创建若干个长度为26的数组，统计每个字符串中每个字母出现的次数。然后再顺序统计全部字符串中同一个字符出现次数最少的个数，即为该字符的共同出现次数。

代码

func commonChars(A []string) []string {
    result := []string{}
    count := make([][26]byte, len(A))
    for i, str := range A {
        for _, c := range str {
            count[i][c-'a']++
        }
    }
    for i:=0; i < 26; i++ {
        var max byte = count[0][i]
        if max == 0 {
            continue
        }
        for j:=1; j < len(A); j++ {
            if count[j][i] == 0 {
                max = 0
                break
            }
            if count[j][i] < max {
                max = count[j][i]
            }
        }
        for max > 0 {
            result = append(result, string(i+'a'))
            max--
        }
    }
    return result
}