Sequential String

Problem Overview

• Compute, for each query in arr, the minimum characters from digit-only s (sequential access) needed to contain any permutation of that query, or -1 if impossible.
• Input: s of '0'-'9' and arr of digit strings; Output: int array with minimal substring length in s per query.
• Constraints: n ≤ 1e5, up to 2e4 queries, total query length ≤ 5e5.
• From Snowflake interviews: string processing problem common in coding interview prep and interview question sets.