Leet code problem 1897: – Redistribute Characters to Make All Strings Equal

You are given an array of strings words (0-indexed).

In one operation, pick two distinct indices i and j, where words[i] is a non-empty string, and move any character from words[i] to any position in words[j]. Return true if you can make every string in words equal using any number of operations, and false otherwise.

Example 1:

Input: words = [“abc”,”aabc”,”bc”]
Output: true
Explanation: Move the first ‘a’ in words[1] to the front of words[2],
to make words[1] = “abc” and words[2] = “abc”.
All the strings are now equal to “abc”, so return true.

Example 2:

Input: words = [“ab”,”a”]
Output: false
Explanation: It is impossible to make all the strings equal using the operation.

Constraints:

1 <= words.length <= 100
1 <= words[i].length <= 100
words[i] consists of lowercase English letters.

Flow Diagram: –

Solution: –

class Solution {
    public boolean makeEqual(String[] words) {
        
        HashMap<Character, Integer> map = new HashMap<>();
        
        for(String str : words){
            
            for(int i=0; i<str.length(); i++){
                char ch = str.charAt(i);
                
                map.put(ch, map.getOrDefault(ch, 0) + 1);
            }
            
        }
        
        for(Character key : map.keySet()){
            
            int freq = map.get(key);
            if(freq % words.length!=0){
                return false;
            }
        }
        
        return true;
    }
}