829. Word Pattern II

Description

Given a pattern and a string str, find if str follows the same pattern.

Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty substring in str.(i.e if a corresponds to s, then b cannot correspond to s. For example, given pattern = "ab", str = "ss", return false.)

You may assume both pattern and str contains only lowercase letters.

Example

Example 1

Input:

pattern = "abab"

str = "redblueredblue"

Output: true

Explanation: "a"->"red","b"->"blue"

Example 2

Input:

pattern = "aaaa"

str = "asdasdasdasd"

Output: true

Explanation: "a"->"asd"

Example 3

Input:

pattern = "aabb"

str = "xyzabcxzyabc"

Output: false

思路：

这个看答案挺简单，但是想不出来，就是把pattern里的字母一个一个的和string的各种长度的substring来试，如果一个字母在mapping里，就看下它后面的符不符合要求，不在mapping里就挨个儿试一遍，如果到最后没有合适的就是False

代码：