uva 10815 Andy's First Dictionary

#include<iostream>#include<cstdio>#include<set>#include<sstream>using namespace std;set<string> dict;int main(){    string s,buf;    while(cin>>s)    {        for(int i=0;i<s.length();i++){            if(isalpha(s[i])) s[i]=tolower(s[i]);            else s[i]=' ';        }        stringstream ss(s);        while(ss>>buf) dict.insert(buf);    }    for(set<string>::iterator it=dict.begin();it!=dict.end();it++)            cout<<*it<<endl;    return 0;}