(Easy) Find Common Characters LeetCode

Posted 2022-08-11 codingyangmao

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;