LeetCode in Kotlin

1961. Check If String Is a Prefix of Array

Easy

Given a string s and an array of strings words, determine whether s is a prefix string of words.

A string s is a prefix string of words if s can be made by concatenating the first k strings in words for some positive k no larger than words.length.

Return true if s is a prefix string of words, or false otherwise.

Example 1:

Input: s = “iloveleetcode”, words = [“i”,”love”,”leetcode”,”apples”]

Output: true

Explanation: s can be made by concatenating “i”, “love”, and “leetcode” together.

Example 2:

Input: s = “iloveleetcode”, words = [“apples”,”i”,”love”,”leetcode”]

Output: false

Explanation: It is impossible to make s using a prefix of arr.

Constraints:

• 1 <= words.length <= 100
• 1 <= words[i].length <= 20
• 1 <= s.length <= 1000
• words[i] and s consist of only lowercase English letters.

Solution

class Solution {
    fun isPrefixString(s: String, words: Array<String?>): Boolean {
        val sb = StringBuilder()
        for (word in words) {
            sb.append(word)
            if (sb.toString() == s) {
                return true
            }
        }
        return false
    }
}

This site is open source. Improve this page.