DataStructure_Algorithm_HandBook_PreForLeetCode

1160. Find Words That Can Be Formed by Characters

You are given an array of strings words and a string chars.

A string is good if it can be formed by characters from chars (each character can only be used once).

Return the sum of lengths of all good strings in words.

Example 1:

Input: words = ["cat","bt","hat","tree"], chars = "atach"
Output: 6
Explanation: The strings that can be formed are "cat" and "hat" so the answer is 3 + 3 = 6.

Example 2:

Input: words = ["hello","world","leetcode"], chars = "welldonehoneyr"
Output: 10
Explanation: The strings that can be formed are "hello" and "world" so the answer is 5 + 5 = 10.

Constraints:

• 1 <= words.length <= 1000
• 1 <= words[i].length, chars.length <= 100
• words[i] and chars consist of lowercase English letters.

Code

We can use hashTable

we can also use Array here

function countCharacters(words, chars) {
    const map = {};
    for (const c of chars) {
        map[c] = (map[c] || 0) + 1;
    }

    let res = 0;

    for (const word of words) {
        const wordMap = {};
        for (const c of word) {
            wordMap[c] = (wordMap[c] || 0) + 1;
        }

        let flag = true;
        for (const c in wordMap) {
            if ((map[c] || 0) < wordMap[c]) {
                flag = false;
                break;
            }
        }

        if (flag) {
            res += word.length;
        }
    }

    return res;
}