[String-easy] 686. Repeated String Match Let A be repeated many times allows B to A substring

1. The title site

https://leetcode.com/problems/repeated-string-match/

2. Title Description

3. subject to the effect

Given two strings, A and B, and so many times allows A to A B substring repeated.

4. Problem-solving ideas

• First, the length B is calculated count how many times the length of the A string, multiple count (i.e., the length of B is not fully divisible A), then the count ++
• Then define a variable of type StringBuilder, so he repeated Add to count A.
• Note: this place is easy to overlook a Class test, i.e., A = "abcd", B = "cdabcdab"

5. AC Code

class Solution {
    public int repeatedStringMatch(String A, String B) {
        int alen = A.length();
        int blen = B.length();
        int count = blen / alen;
        if(blen % alen != 0) count++;
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < count; i++){
            sb.append(A);
        }
        if(!sb.toString().contains(B)){
            sb.append(A);
            count++;
            if(!sb.toString().contains(B)) return -1;
        }
        return count;
    }
}

6. similar source

[1] 459. Repeated Substring Pattern topic site: https://leetcode.com/problems/repeated-substring-pattern/