leetcode 151. Reverse Words in a String 字符串分割逆序 + stringstream分割字符串

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

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

Update (2015-02-12):
For C programmers: Try to solve it in-place in O(1) space.

对于Java实现，直接分割字符串然后逆序即可。

代码如下：

public class Solution 
{
    public String reverseWords(String s) 
    {
        if(s==null || s.length()<=0)
            return s;

        s=s.trim();
        String []res=s.split("\\s+");
        if(res.length<=1)
            return s;

        StringBuilder builder=new StringBuilder();
        builder.append(res[res.length-1]);
        for(int i=res.length-2;i>=0;i--)
            builder.append(" "+res[i]);
        return builder.toString();
    }
}

下面是C++的做法，就是做一个字符串分割，直接使用stringstream来做分割即可，很好用的

代码如下：

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

using namespace std;




class Solution 
{
public:
    void reverseWords(string &s) 
    {
        stringstream ss(s);
        vector<string> res;
        string tmp = "";
        while (ss >> tmp)
            res.push_back(tmp);

        if (res.size() ==0)
            s = "";
        else
        {
            s = res[res.size() - 1];
            for (int i = res.size() - 2; i >= 0; i--)
                s += " " + res[i];
        }
    }
};