Given two strings A and B, find the minimum number of times A has to be repeated such that B is a substring of it. If no such solution, return -1.
For example, with A = "abcd" and B = "cdabcdab".
Return 3, because by repeating A three times (“abcdabcdabcd”), B is a substring of it; and B is not a substring of A repeated two times ("abcdabcd").
Note:
The length of A and B will be between 1 and 10000.
class Solution {
public int repeatedStringMatch(String A, String B) {
int count = 0;
StringBuilder sb = new StringBuilder();
while (sb.length() < B.length()) {
sb.append(A);
count++;
}
if (sb.toString().contains(B))
return count;
if (sb.append(A).toString().contains(B)) //关键在于还要再repeat一次，之后就没有必要再repeat了
return ++count;
return -1;
}
}
原文：https://www.cnblogs.com/MarkLeeBYR/p/10688274.html