Easy

Quiz

#482 License Key Formatting

APPROACH

Given a license key string s (containing alphanumeric characters and dashes) and an integer k, strip all dashes, uppercase all letters, then regroup the characters into segments of size k separated by dashes. The first segment may be shorter than k but must contain at least one character.

Return the reformatted string.

Example 1:

Input: s = "5F3Z-2e-9-w", k = 4

Output: "5F3Z-2E9W"

Explanation: The string s has been split into two parts, each part has 4 characters.

Note that the two extra dashes are not needed and can be removed.

Example 2:

Input: s = "2-5g-3-J", k = 2

Output: "2-5G-3J"

Explanation: The string s has been split into three parts, each part has 2 characters except the first part as it could be shorter as mentioned above.

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What is the optimal approach for this problem?