UVa 10815 - Andy's First Dictionary

Problem B: Andy's First Dictionary
Time limit: 3 seconds

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

 1 // UVa10815 Andy's First Dictionary

 2 // Rujia Liu

 3 // 题意：输入一个文本，找出所有不同的单词（连续字母序列），按字典序从小到大输出。单词不分大小写。

 4 // 代码由刘汝佳提供，我是在我的水平下，加以注释，学习大神的思想

 5 #include<iostream>

 6 #include<string>

 7 #include<set>

 8 #include<sstream>//为了使用stringstream

 9 using namespace std;

10 

11 set<string> dict;

12 string s, buf;

13 

14 int main() {

15   while(cin >> s) {

16     for(int i = 0; i < s.length(); i++)

17       if(isalpha(s[i])) s[i] = tolower(s[i]); else s[i] = ' ';//isalpha判断是否为字母，tolower转化成小写

18     stringstream ss(s);//创建字符串流ss

19     while(ss >> buf) dict.insert(buf);//重点学习插入

20   }

21   for(set<string>::iterator it = dict.begin(); it != dict.end(); ++it)

22     cout << *it << "\n";

23   return 0;

24 }

isalpha判断是否为字母
tolower转化成小写
set中元素只出现一次 且 从小到大排列
set<T>::iterator it这里的it相对于指针的用法
//代码中的dict.insert()是插入 重点学习