- Difficulty: Medium
- Tags: LeetCode, Medium, Two Pointers, String, leetcode-186, O(n), O(1), 🔒
Problem
Given a character array s
, reverse the order of the words.
A word is defined as a sequence of non-space characters. The words in s
will be separated by a single space.
Your code must solve the problem in-place, i.e. without allocating extra space.
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Example 1:
Input: s = ["t","h","e"," ","s","k","y"," ","i","s"," ","b","l","u","e"] Output: ["b","l","u","e"," ","i","s"," ","s","k","y"," ","t","h","e"]
Example 2:
Input: s = ["a"] Output: ["a"]
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Constraints:
1 <= s.length <= 105
s[i]
is an English letter (uppercase or lowercase), digit, or space' '
.- There is at least one word in
s
. s
does not contain leading or trailing spaces.- All the words in
s
are guaranteed to be separated by a single space.