Easy

Quiz

#1417 Reformat The String

APPROACH

Given an alphanumeric string s (lowercase letters and digits), rearrange its characters so that no two adjacent characters are of the same type (letters and digits must alternate). Return any valid reformatted string, or an empty string if rearrangement is impossible.

Example 1:

Input: s = "a0b1c2"

Output: "0a1b2c"

Explanation: No two adjacent characters have the same type in "0a1b2c". "a0b1c2", "0a1b2c", "0c2a1b" are also valid permutations.

Example 2:

Input: s = "leetcode"

Output: ""

Explanation: "leetcode" has only characters so we cannot separate them by digits.

Example 3:

Input: s = "1229857369"

Output: ""

Explanation: "1229857369" has only digits so we cannot separate them by characters.

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