UVA10815 Andy's First Dictionary(STL)

题面：

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

 

分析：

很明显是set的应用，主要麻烦的地方就是字符串的处理了，啊看见字符串就烦.jpg。话说我现在才知道set内部是会自动按照字典序排序的。

 

AC代码：

#include<bits/stdc++.h>
using namespace std;
string str1, str2;

struct cmp{
	bool operator()(const string &a, const string &b){
		return a < b;
	}
};

set<string,cmp>s;

int main(){
	
	while(cin>>str1){
		for(int i = 0; i < str1.length(); i++){
			if(isalpha(str1[i])){
				if(str1[i] >= 'A' && str1[i] <= 'Z') str1[i] += 32;
			}
			else str1[i] = ' ';
		}
		istringstream ss(str1);
		while(ss>>str2) s.insert(str2);
		str1.clear();
	}
	
	for(set<string,cmp>::iterator iter = s.begin(); iter != s.end(); iter++){
		cout<<*iter<<endl;
	}
	return 0;
}