Interview Questions/Coding/Distinct Letter Packet

Distinct Letter Packet

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Easy

Distinct Letter Packet

A packet contains n lowercase symbols captured from a noisy set-notation feed. The same symbol may appear more than once because the feed can repeat observations. For each packet, count how many different symbols are present. Input Format: The first line contains t, the number of test cases. Each test case contains n followed by n lowercase symbols. Output Format: For each test case, print the number of distinct symbols.

Examples

Example 1
Input:
1
4
a b c a
Output:
3

Explanation: The packet contains a, b, and c as distinct symbols.

Approach hint

Start with the simplest clear approach, explain the trade-off, then move toward the cleaner answer.

Common mistake

Skipping assumptions, edge cases, or trade-offs can make an otherwise good answer feel incomplete.

solution.cpp