UVA - 10815 Andy's First Dictionary

#include <iostream>
#include <cstring>
#include <algorithm>
#include <set>
using namespace std;

set<string> out;

int main()
{
    string s,temp;
    while(cin>>s)
    {
        int len(s.size());
        for(int i=0;i<len;i++) s[i] = tolower(s[i]);
        temp.clear();

        for(int i=0;i<len;i++)
        {
            if('a'<=s[i]&&s[i]<='z') temp.push_back(s[i]);
            else
            {
                if(temp.size() != 0)
                {
                    out.insert(temp);
                    temp.clear();
                }
            }
            if(i == len - 1)
            {
                if(temp.size() != 0)
                {
                    out.insert(temp);
                }
            }
        }
    }
    for(set<string>::iterator it=out.begin();it!=out.end();it++)
        cout<<*it<<endl;
}