UVA 10815 Andy's First Dictionary（stringstream，set等）

Andy’s First Dictionary
Andy, 8, has a dream - he wants to produce his very own dictionary. This is not an easy task for him, as the number of words that he knows is, well, not quite enough. Instead of thinking
up all the words himself, he has a briliant idea. From his bookshelf he would pick one of his favourite story books, from which he would copy out all the distinct words. By arranging the words in alphabetical order, he is done! Of course, it is a really time-consuming
job, and this is where a computer program is helpful. You are asked to write a program that lists all the different words in the input text. In this problem, a word is defined as a consecutive sequence of alphabets, in upper and/or lower case. Words with only
one letter are also to be considered. Furthermore, your program must be CaSe InSeNsItIvE. For example, words like“Apple”, “apple” or “APPLE” must be considered the same.
Input
The input file is a text with no more than 5000 lines. An input line has at most 200 characters. Input is terminated by EOF.
Output
Your output should give a list of different words that appears in the input text, one in a line. The words should all be in lower case, sorted in alphabetical order. You can be sure that he number of distinct words in the text does not exceed 5000.
Sample Input
Adventures in Disneyland
Two blondes were going to Disneyland when they came to a fork in the road. The sign read: “Disneyland Left.”
So they went home.
Sample Output
a
adventures
blondes
came

disneyland
fork

going
home

in

left

read

road

sign
so

the

they
to

two
went

were
when

#include<iostream>
#include<stdio.h>
#include<set>
#include<string>
#include<sstream>
#include<string.h>
using namespace std;
set<string> b;
	
int main(){
	string a,buf;

	while(cin>>a){
		int l=a.length();
		for(int i=0;i<l;i++){
			if(isalpha(a[i])) a[i]=tolower(a[i]);
			else a[i]=' ';
		}
		stringstream ss(a);
		while(ss>>buf){
			b.insert(buf);
		}
		
		}
		set<string>::iterator it;
		for(it=b.begin();it!=b.end();it++){
			cout<<*it<<endl;
	}
	return 0;
}

1. stl中set的用法：
   头文件#include
   定义 set a;
   插入a.insert();
   输出:set::iterator it;
   for(it=a.begin();it!=a.end();it++){
   cout<<*it<<endl;}
2. stringstream的用法
   头文件：#include
   将输入进入数据流：stringstream ss(a);
   输出至b中：ss>>b;

3文件读入：
freopen(“text.txt”,“r”,stdin);