from typing import List
from collections import Counter

class Solution:
    def commonChars(self, words: List[str]) -> List[str]:
        # Start with the letter counts of the first word
        common = Counter(words[0])
        for word in words[1:]:
            # Intersect with the counts from the next word
            common &= Counter(word)
        # Expand the counts back into a list of characters
        result = []
        for char, count in common.items():
            result.extend([char] * count)
        return result
      

#include <vector>
#include <string>
#include <algorithm>

using namespace std;

class Solution {
public:
    vector<string> commonChars(vector<string>& words) {
        vector<int> minFreq(26, INT_MAX);
        for (const string& word : words) {
            vector<int> freq(26, 0);
            for (char c : word) {
                freq[c - 'a']++;
            }
            for (int i = 0; i < 26; ++i) {
                minFreq[i] = min(minFreq[i], freq[i]);
            }
        }
        vector<string> res;
        for (int i = 0; i < 26; ++i) {
            for (int j = 0; j < minFreq[i]; ++j) {
                res.push_back(string(1, i + 'a'));
            }
        }
        return res;
    }
};
      

import java.util.*;

class Solution {
    public List<String> commonChars(String[] words) {
        int[] minFreq = new int[26];
        Arrays.fill(minFreq, Integer.MAX_VALUE);
        for (String word : words) {
            int[] freq = new int[26];
            for (char c : word.toCharArray()) {
                freq[c - 'a']++;
            }
            for (int i = 0; i < 26; i++) {
                minFreq[i] = Math.min(minFreq[i], freq[i]);
            }
        }
        List<String> result = new ArrayList<>();
        for (int i = 0; i < 26; i++) {
            for (int j = 0; j < minFreq[i]; j++) {
                result.add(String.valueOf((char)(i + 'a')));
            }
        }
        return result;
    }
}
      

/**
 * @param {string[]} words
 * @return {string[]}
 */
var commonChars = function(words) {
    let minFreq = new Array(26).fill(Infinity);
    for (let word of words) {
        let freq = new Array(26).fill(0);
        for (let c of word) {
            freq[c.charCodeAt(0) - 97]++;
        }
        for (let i = 0; i < 26; i++) {
            minFreq[i] = Math.min(minFreq[i], freq[i]);
        }
    }
    let res = [];
    for (let i = 0; i < 26; i++) {
        for (let j = 0; j < minFreq[i]; j++) {
            res.push(String.fromCharCode(i + 97));
        }
    }
    return res;
};