Description
Given a string s. Pick the smallest character, append it and remove it. Then pick the largest remaining, append and remove. Repeat alternating until empty.
Examples
Input:
s = "aaaabbbbcccc"Output:
"abccbaabccba"Explanation:
Alternating order.
Input:
s = "a"Output:
"abccbaabccba"Explanation:
A single-character string is processed by the alternating sort and reverse operations.
Input:
s = "ddaabbcc"Output:
"abcddbca"Explanation:
Start by picking smallest available chars: a, b, c, d. Then pick largest available: d, c, b, a. This demonstrates the alternating pattern of selecting minimum then maximum available characters until all are used.
Constraints
- •
1 ≤ s.length ≤ 500