# ---
# title: 686. Repeated String Match
# id: problem686
# author: Tian Jun
# date: 2020-10-31
# difficulty: Medium
# categories: String
# link: <https://leetcode.com/problems/repeated-string-match/description/>
# hidden: true
# ---
# 
# Given two strings `a` and `b`, return the minimum number of times you should
# repeat string `a` so that string `b` is a substring of it. If it is impossible
# for `b`​​​​​​ to be a substring of `a` after repeating it, return `-1`.
# 
# **Notice:**  string `"abc"` repeated 0 times is `""`,  repeated 1 time is
# `"abc"` and repeated 2 times is `"abcabc"`.
# 
# 
# 
# **Example 1:**
# 
#     
#     
#     Input: a = "abcd", b = "cdabcdab"
#     Output: 3
#     Explanation: We return 3 because by repeating a three times "ab **cdabcdab** cd", b is a substring of it.
#     
# 
# **Example 2:**
# 
#     
#     
#     Input: a = "a", b = "aa"
#     Output: 2
#     
# 
# **Example 3:**
# 
#     
#     
#     Input: a = "a", b = "a"
#     Output: 1
#     
# 
# **Example 4:**
# 
#     
#     
#     Input: a = "abc", b = "wxyz"
#     Output: -1
#     
# 
# 
# 
# **Constraints:**
# 
#   * `1 <= a.length <= 104`
#   * `1 <= b.length <= 104`
#   * `a` and `b` consist of lower-case English letters.
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
