题目：
Searching and sorting are part of the theory and practice of computer science. For example, binary search provides a good example of an easy-to-understand algorithm with sub-linear complexity. Quicksort is an efficient
[average case] comparison based sort.
KWIC-indexing is an indexing method that permits efficient ``human search'' of, for example, a list of titles.
Given a list of titles and a list of ``words to ignore'', you are to write a program that generates a KWIC (Key Word In Context) index of the titles. In a KWIC-index, a title is listed once for each keyword that occurs in the title. The KWIC-index is alphabetized by keyword.
Any word that is not one of the ``words to ignore'' is a potential keyword.
For example, if words to ignore are ``the, of, and, as, a'' and the list of titles is:
Descent of Man
The Ascent of Man
The Old Man and The Sea
A Portrait of The Artist As a Young Man
A KWIC-index of these titles might be given by:
a portrait of the ARTIST as a young man
the ASCENT of man
DESCENT of man
descent of MAN
the ascent of MAN
the old MAN and the sea
a portrait of the artist as a young MAN
the OLD man and the sea
a PORTRAIT of the artist as a young man
the old man and the SEA
a portrait of the artist as a YOUNG man
input
The input is a sequence of lines, the string :: is used to separate the list of words to ignore from the list of titles. Each of the words to ignore appears in lower-case letters on a line by itself and is no more than 10 characters in length. Each title appears on a line by itself and may consist of mixed-case (upper and lower) letters. Words in a title are separated by whitespace. No title contains more than 15 words.
There will be no more than 50 words to ignore, no more than than 200 titles, and no more than 10,000 characters in the titles and words to ignore combined. No characters other than 'a'-'z', 'A'-'Z', and white space will appear in the input.
output
The output should be a KWIC-index of the titles, with each title appearing once for each keyword in the title, and with the KWIC-index alphabetized by keyword. If a word appears more than once in a title, each instance is a potential keyword.
The keyword should appear in all upper-case letters. All other words in a title should be in lower-case letters. Titles in the KWIC-index with the same keyword should appear in the same order as they appeared in the input file. In the case where multiple instances of a word are keywords in the same title, the keywords should be capitalized in left-to-right order.
Case (upper or lower) is irrelevant when determining if a word is to be ignored.
The titles in the KWIC-index need NOT be justified or aligned by keyword, all titles may be listed left-justified.
sample input
is
the
of
and
as
a
but
::
Descent of Man
The Ascent of Man
The Old Man and The Sea
A Portrait of The Artist As a Young Man
A Man is a Man but Bubblesort IS A DOG
sample output
a portrait of the ARTIST as a young man
the ASCENT of man
a man is a man but BUBBLESORT is a dog
DESCENT of man
a man is a man but bubblesort is a DOG
descent of MAN
the ascent of MAN
the old MAN and the sea
a portrait of the artist as a young MAN
a MAN is a man but bubblesort is a dog
a man is a MAN but bubblesort is a dog
the OLD man and the sea
a PORTRAIT of the artist as a young man
the old man and the SEA
a portrait of the artist as a YOUNG man
题解：::之前的都是要忽略的单词 ，在后面的句子里出了可忽略的单词外都是关键字，将所有关键字找出，用map将关键字和他所在的句子关联起来，并将其关联的句子输出，对应关键字大写其他单词小写，有相同关键字就按输入顺序输出。
#include <iostream>
#include <cstdio>
#include <map>//按key值自动从小到大排序
#include <set>
#include <string>
using namespace std;
string key[55], title[205], temp, temp1;
multimap <string, string> p;//可存储重复的key
set<string> s;
int main() {
int n = 0, m = 0;
while (getline(cin, key[n])) {
if (key[n][0] == ':' && key[n][1] == ':')
break;
else {
s.insert(key[n]);
n++;
}
}
while (getline(cin, title[m])) {
temp = temp1 = "";
int len = title[m].size();
for (int i = 0; i < len; i++)
title[m][i] = tolower(title[m][i]);
for (int i = 0; i < len + 1; i++)
if (isalpha(title[m][i]))//如果是字母
temp += title[m][i];
else {
if (s.count(temp) == 0) {//set.count(temp)可得到temp在set集合中出现的次数
for (int k = 0; k < temp.size(); k++)
temp[k] = toupper(temp[k]);//关键字转成大写
temp1 = title[m];
temp1.replace(i - temp.size(), temp.size(), temp);//string.replace(起始位置，替换长度，用于替换的string)
p.insert(pair<string, string>(temp, temp1));//map的插入语句
temp1 = title[m];
}
temp = "";
}
m++;
}
multimap <string, string>::iterator it = p.begin();//定义map的迭代器并赋初始值
for (; it != p.end(); it++)
cout << it->second << endl;
return 0;
}