【LeetCode】151. Reverse Words in a String

最新推荐文章于 2024-01-04 11:20:32 发布

转载最新推荐文章于 2024-01-04 11:20:32 发布 · 54 阅读

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原文链接：http://www.cnblogs.com/ganganloveu/p/4091682.html

本文介绍了一种遍历字符串并逐个反转单词的方法。通过跳过空格和收集非空字符来形成单词，最终将收集到的单词按逆序连接以完成字符串反转。文章详细解释了如何处理输入字符串中的空格和多个空格之间的单词。

Reverse Words in a String

Given an input string, reverse the string word by word.

For example,
Given s = "the sky is blue",
return "blue is sky the".

click to show clarification.

Clarification:

What constitutes a word?
A sequence of non-space characters constitutes a word.
Could the input string contain leading or trailing spaces?
Yes. However, your reversed string should not contain leading or trailing spaces.
How about multiple spaces between two words?
Reduce them to a single space in the reversed string.

一次遍历，将所有遇到的单词加在头部。

class Solution {
public:
    void reverseWords(string &s) 
    {
        string rs = "";
        int i = 0;
        while(true)
        {
            // skip leading space
            while(i < s.size() && s[i] == ' ')
                i ++;
            string word = "";
            // s[i] points to first non-space
            while(i < s.size() && s[i] != ' ')
            {
                word += s[i];
                i ++;
            }
            if(word != "")
                rs = word + " " + rs;
            else    // i == s.size()
                break;
        }
        if(rs != "")
            rs.erase(rs.end()-1);   // if rs contains words, erase the last space
        s = rs;
    }
};

转载于:https://www.cnblogs.com/ganganloveu/p/4091682.html