Sequence Check
Prereq: Knapsack Intro
Given 2 strings determine how many distinct subsequences of s equal t.
A subsequence of s is a the original sequence s with some characters deleted.
The answer is guaranteed to be less than 2^31-1.
Constraints
1 <= s.length, t.length <= 100001
The strings s and t will only contain lowercase english letters
Examples
Example 1
Input: s = "rabbbit", t = "rabbit"
Output: 3
Explanation:
You can remove any of the 3 middle b values from s to make the t value
Try it Yourself
Title
Script
Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.
Contrary to popular belief, Lorem Ipsum is not simply random text.
1 >>> a = [1, 2, 3] 2 >>> a[-1] 3 3