LeetCode in Kotlin

1160. Find Words That Can Be Formed by Characters

Easy

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.

Solution

class Solution {
    fun countCharacters(words: Array<String>, chars: String): Int {
        var length = 0
        val map: MutableMap<Char, Int> = HashMap()
        for (c in chars.toCharArray()) {
            val count = map.getOrDefault(c, 0)
            map[c] = count + 1
        }
        for (word in words) {
            if (canForm(word, map)) {
                length += word.length
            }
        }
        return length
    }

    private fun canForm(word: String, map: Map<Char, Int>): Boolean {
        val tmp: MutableMap<Char, Int> = HashMap(map)
        for (c in word.toCharArray()) {
            if (tmp.containsKey(c) && tmp.getValue(c) > 0) {
                val count = tmp.getValue(c)
                tmp[c] = count - 1
            } else {
                return false
            }
        }
        return true
    }
}

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