everystep

1002. 查找共用字符

class Solution {
public:
    vector<string> commonChars(vector<string>& words) {
        vector<int> minFreq(26, INT_MAX);
        vector<int> freq(26, 0);
        vector<string> result;

        for (const string& word : words) {
            fill(freq.begin(), freq.end(), 0);
            for (char c : word) {
                ++freq[c - 'a'];
            }
            for (int i = 0; i < 26; ++i) {
                minFreq[i] = min(minFreq[i], freq[i]);
            }
        }

        for (int i = 0; i < 26; ++i) {
            for (int j = 0; j < minFreq[i]; ++j) {
                result.push_back(string(1, i + 'a'));
            }
        }

        return result;
    }
};