1002. Find Common Characters
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.
Example 1:
Input: ["bella","label","roller"] Output: ["e","l","l"]
Example 2:
Input: ["cool","lock","cook"] Output: ["c","o"]
Note:
1 <= A.length <= 100
1 <= A[i].length <= 100
Ai is a lowercase letter
難度: easy
題目:給定字串陣列A僅由小字元組成,返回所有在所有字串中都出現過的字元,包括重複。例如,如果一個字元在所有字串出現了3次而非4次,則返回結果中要包含3次。返回順序不限。
思路:每個字串一個統計表。
Runtime: 7 ms, faster than 100.00% of Java online submissions for Find Common Characters.
Memory Usage: 38.1 MB, less than 100.00% of Java online submissions for Find Common Characters.
class Solution { public List<String> commonChars(String[] A) { int n = A.length; int[][] cc = new int[n][26]; for (int i = 0; i < n; i++) { for (char c : A[i].toCharArray()) { cc[i][c - 'a']++; } } List<String> result = new ArrayList<>(); for (int i = 0; i < 26; i++) { int minCount = 100; for (int j = 0; j < n; j++) { minCount = Math.min(minCount, cc[j][i]); } for (int j = 0; j < minCount; j++) { result.add(String.valueOf((char) (i + 'a'))); } } return result; } }