C++字符串 单词倒置

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>

using namespace std;

void out(string n)
{
     cout << n << ' ';
}

int main()
{

     char a[]="what are you doing";//变成"tahw era uoy gniod"
     vector <string> iv;
     const char * split=" ";
     char * p;
     p = strtok (a,split);
     string s;
     while(p!=NULL)
     {
          s = p;
          reverse(s.begin(),s.end());
          iv.push_back(s);
          p = strtok(NULL,split);
     }
     s.~string();
     for_each(iv.begin(),iv.end(),out);
     cout<<endl;
     system("pause");
     return 0;
}