Two lab samples are recorded as lowercase strings a and b. A shared run is a block of consecutive characters that appears (contiguously) in both. Return the length of the longest shared run; return 0 if the strings share no character.
Examples
Input: a = "harborlight", b = "neighborly"
Output: 4
Explanation: "borl" appears in both.
Input: a = "abc", b = "xyz"
Output: 0
Constraints
0 <= len(a), len(b) <= 300- Lowercase letters only.
- Target complexity: O(len(a) * len(b)).
Goals
- Distinguish a contiguous substring state from the subsequence state
- Reset the table entry to zero when characters differ