面试经典150题,面试题集锦

文章目录 一、题目二、题解 p> 一、题目 p>Given an input string 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 at least one space.

Return a string of the words in reverse order concatenated by a single space.

Note that s may contain leading or trailing spaces or multiple spaces between two words. The returned string should only have a single space separating the words. Do not include any extra spaces.

Example 1:

Input: s “the sky is blue”
Output: “blue is sky the”
Example 2:

Input: s hello world
Output: “world hello”
Explanation: Your reversed string should not contain leading or trailing spaces.
Example 3:

Input: s “a good example”
Output: “example good a”
Explanation: You need to reduce multiple spaces between two words to a single space in the reversed string.

Constraints:

1 < s.length < 104
s contains English letters (upper-case and lower-case), digits, and spaces ’ .
There is at least one word in s.

Follow-up: If the string data type is mutable in your language, can you solve it in-place with O(1) extra space?

strong>题目来源 leetcode

二、题解 code class="prism language-cpp">class Solution {public: string reverseWords(string s) { vector<string> tmp; istringstream ss(s); string token; while(getline(ss,token, )) tmp.push_back(token); string res ; int n tmp.size(); for(int i n - 1;i > 0;i--){ if(tmp[i] ! ){ res tmp[i]; res ; } } //去除末尾空格 while(res.back() ) res.pop_back(); return res; }};/pre>