Ashley Loves Numbers (Financial Engineer)

Problem Overview

• For each query range [n, m], count how many integers have all unique digits (no repeats).
• Input: q (≤ 1e5) pairs (n, m) with 1 ≤ n ≤ m ≤ 10^6; Output: a count per query, one per line.
• Context: Financial Engineer theme where Ashley loves numbers without repeating digits.
• Source: Bloomberg interviews; a coding interview problem and common interview question.