Available question text
Count how many subsequences of a given sequence/string satisfy the problem's "good" criterion (typically non-trivial pattern or property) — return the total (usually modulo 10^9+7). This generally requires dynamic programming or combinatorics to accumulate subsequence counts efficiently while handling duplicates and large input sizes rather than brute-force enumeration.
Related questions
Continue with questions that share topics or the same question type.
Sources · 1 reference
These records explain where the question appears. A company tag or candidate report does not guarantee a future interview question.
Hello Interview · 1 record
No company association
Leetcode 2539. Count the Number of Good Subsequences
Reported date not specified · 0 source reports
Source snapshot: Nov 12, 2026
View source