翻转单词顺序列

题目描述

例如，“student. a am I”。正确的句

class Solution {
public:
    string ReverseSentence(string str) {
        if(str.size()==0)
            return str;
        if (str.size() == 0)
            return str;

        reverseWord(str, 0, str.size() - 1);

        int start = 0;
        int end = 0;

        for (int i = 0; i<=str.size(); i++) {
            if (str[i] == ' '|| i == str.size()) {
                end = i - 1;
                reverseWord(str, start, end);
                start = i + 1;
            }
        }

        return str;
    }
   
    void reverseWord(string& str,int start,int end){
        if(str.size() == 0)
            return ;
        
       while(start < end){
           char tmp = str[start];
           str[start] = str[end];
           str[end] = tmp;
              ++ start;
            --end;        
       }
        
    }
};

 

子应该是“I am a student.”。