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.
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.
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.
问题：从一段输入中构建一个字典...都要写成小写...
分析：用了stl中的set...然后就是有个技巧是用的stringstream...简直神器...
#include<iostream> #include<set> #include<string> #include<sstream> using namespace std; set<string> dic; int main(){ string str,temp; int t=0; while(cin>>str){ for(int i=0;i<str.size();i++){ if(isalpha(str[i])){ str[i]=tolower(str[i]); } else{ str[i]=' ';//把所有除字母以外的符号都替换成空格...因为空格是stringstream的分割符号... } } stringstream ss; ss<<str; //把处理过的字符串输入stringstream... while(ss>>temp){ dic.insert(temp); } } for(set<string>::iterator it=dic.begin();it!=dic.end();it++) cout<<*it<<endl; }