单词翻转

#include<iostream>
#include<string>
using namespace std;
class ReverseWords{
public:
ReverseWords(string* wo):words(wo){}
void reverse_()
{
int length=words->size();
int begin=-1,end=-1;
for(int i=0;i<length;++i){
if(begin==-1&&words->at(i)==' ')//去掉 字符串最前面的空格
continue;
if(begin==-1)//记录第一个非空格字符出现的位置
{
begin=i;
continue;
}
if(words->at(i)==' ')//记录结束位置
end=i-1;
else if(i==length-1)
end=i;
else
continue;
reverse__(begin,end); //1.字母翻转
begin=-1,end=-1;
}
reverse__(0,length-1); //2.单词翻转
}
private:
void reverse__(int begin,int end) //
{

while(begin<end)

{
char t=words->at(begin);
words->at(begin)=words->at(end);
words->at(end)=t;
++begin;
--end;
}
}
string* words;
};
int main(){
string s="I am a student.";
ReverseWords r(&s);
r.reverse_();
cout<<s<<endl;
return 0;
}