UVA 10815 Andy's First Dictionary

#include <iostream>#include <cstdio>#include <algorithm>#include <set>#include <string>#include <sstream>using namespace std;int main(){    set<string> dict;    string s,t;    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>>t)            dict.insert(t);    }    for(set<string>::iterator it=dict.begin();it!=dict.end();it++)    {        cout<<*it<<endl;    }    return 0;}