调试器代码学习

#include <iostream>
#include<string>
#include<cctype>
using namespace std;
int main()
{
    string currword,preword;
    cout<<"please enter some word (ctrl+z  to end)"<<endl;
    while(cin>>currword)
    {
        #ifndef NDEBUG
        cout<<currword<<" ";
        #endif
       if(!isupper(currword[0]))
            continue;
        if(currword==preword)
            break;
        else
            preword=currword;

  }

   if(currword==preword&&!currword.empty())
        cout<<"The repeated word"<<currword<<endl;
    else
        cout<<"There  is no repeated word"<<endl;
    return 0;
}