<p>You are given an array of strings <code>words</code> and a string <code>chars</code>.</p>

<p>A string is <strong>good</strong> if it can be formed by characters from <code>chars</code> (each character can only be used once).</p>

<p>Return <em>the sum of lengths of all good strings in words</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> words = [&quot;cat&quot;,&quot;bt&quot;,&quot;hat&quot;,&quot;tree&quot;], chars = &quot;atach&quot;
<strong>Output:</strong> 6
<strong>Explanation:</strong> The strings that can be formed are &quot;cat&quot; and &quot;hat&quot; so the answer is 3 + 3 = 6.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> words = [&quot;hello&quot;,&quot;world&quot;,&quot;leetcode&quot;], chars = &quot;welldonehoneyr&quot;
<strong>Output:</strong> 10
<strong>Explanation:</strong> The strings that can be formed are &quot;hello&quot; and &quot;world&quot; so the answer is 5 + 5 = 10.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= words.length &lt;= 1000</code></li>
	<li><code>1 &lt;= words[i].length, chars.length &lt;= 100</code></li>
	<li><code>words[i]</code> and <code>chars</code> consist of lowercase English letters.</li>
</ul>

// class Solution {
// public:
//     int countCharacters(vector<string>& words, string chars) {
//         int n = words.size();
        
//         unordered_map<char,int> mp; //TC-O(1) for average  ,SC-O(n)
//         for(auto ch:chars)
//             mp[ch]++;
        
       
//         int sum = 0;
//         for(int i=0; i<n; i++){ //O(n)
//            bool makeGoodString = true;
//             unordered_map<char,int> mp2;
//             for(int j=0; j<words[i].size(); j++){  //O(m)
//                 if(++mp2[words[i][j]] > mp[words[i][j]]){
//                     makeGoodString = false;
//                     break;
//                 }
//             }
//             if(makeGoodString) sum+=words[i].size();
           
//      }
        
//         return sum;
//     }
// };

//TC-O(1*n*m) = O(n)
//SC-O(n)



class Solution {
public:
    int countCharacters(vector<string>& words, string chars) {
        int n = words.size();
        
        vector<int> charFreq(26,0); //TC-O(26) for average  ,SC-O(n)
        for(auto ch:chars)
            charFreq[ch-'a']++;
        
       
        int sum = 0;
        for(string s:words){ //O(n)
           bool makeGoodString = true;
            vector<int> wordFreq(26,0);
            for(char ch : s){  //O(m)
                if(++wordFreq[ch-'a'] > charFreq[ch-'a']){
                    makeGoodString = false;
                    break;
                }
            }
            if(makeGoodString) sum+=s.size();
           
     }
        
        return sum;
    }
};


//TC-O(n)
//SC-O(26)
26004