Day 45.2.txt

1961. Check If String Is a Prefix of Array

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.



class Solution {
    public boolean isPrefixString(String s, String[] w) {
        int i=0,k=s.length(),l=0;
        String p="";
        while(l!=k&&i<w.length)
        {
            l=l+w[i].length();
            p=p+w[i];
            i++;
        }
        System.out.println(p);
        return p.equals(s) ? true : false;
    }
}