题目:
Given a singly linked list L: L0→L1→…→Ln-1→Ln,reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→…
You must do this in-place without altering the nodes' value ......
344. Reverse String
Write a function that takes a string as input and returns the string reversed.
Example:Given s = "hello", return "olleh".
clas ......