(Easy) Find Common Characters LeetCode

Description

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. 1 <= A.length <= 100
2. 1 <= A[i].length <= 100
3. A[i][j] is a lowercase letter

Accepted

33,870

Submissions

51,601

Solution

class Solution {
    public List<String> commonChars(String[] A) {

        if(A ==null || A.length==0){
            return null;
        }

        List<String> list = new ArrayList<String>();

        for(int i = 0; i< A[0].length(); i++){

            Character ch = A[0].charAt(i);

            int count = Count(A[0], ch);

            boolean flag = true;

            for(int j = 1; j<A.length; j++)
            {

                    if(!check(A[j],ch)){

                        flag = false;
                    }

                count = count> Count(A[j],ch)? Count(A[j],ch): count;

            }

            if(flag &&!list.contains(Character.toString(ch)) ){
               for(int t =0; t<count;t++){
                   list.add(Character.toString(ch));
               }
            }
        }

        return list;

    }

    public boolean check(String str, Character ch){

        for(int i = 0; i<str.length();i++){

            if(str.charAt(i)== ch){
                return true;
            }
        }

        return false;
    }

    public int Count(String str, Character ch){

        int count = 0;
        for(int i = 0; i<str.length();i++){
            if(str.charAt(i)==ch){
                count++;
            }
        }
        return count;
    }

}

原文地址：https://www.cnblogs.com/codingyangmao/p/11387420.html