Pattern as subsequence

Question

Pattern as subsequence Given a string s and a pattern, write a function to find and return the number of times this pattern appears as a subsequence in the string. Example 1 > - **Input:** s = abacdebgc, pattern = abc > - **Output:** 4 > - **Explanation:** abc appears four times as a subsequence in the string. Example 2 > - **Input:** s = xyzabc, pattern = xzc > - **Output:** 1 > - **Explanation:** xzc appears once as a subsequence in the string. Example 3 > - **Input:** s = abc, pattern = def > - **Output:** 0 > - **Explanation:** The pattern never appears in the string as a subsequence.

Accepted Answer

Optimal Solution: Time Complexity O(N^2), Space Complexity O(1). Codeintuition provides an interactive coding environment for this problem.