POJ-1488(字符串应用)

Description

TEX is a typesetting language developed by Donald Knuth. It takes source text together with a few typesetting instructions and produces, one hopes, a beautiful document. Beautiful documents use double-left-quote and double-right-quote to delimit quotations, rather than the mundane " which is what is provided by most keyboards. Keyboards typically do not have an oriented double-quote, but they do have a left-single-quote ` and a right-single-quote '. Check your keyboard now to locate the left-single-quote key ` (sometimes called the "backquote key") and the right-single-quote key ' (sometimes called the "apostrophe" or just "quote"). Be careful not to confuse the left-single-quote ` with the "backslash" key \. TEX lets the user type two left-single-quotes `` to create a left-double-quote and two right-single-quotes '' to create a right-double-quote. Most typists, however, are accustomed to delimiting their quotations with the un-oriented double-quote ".

If the source contained
"To be or not to be," quoth the bard, "that is the question."

then the typeset document produced by TEX would not contain
the desired form: "To be or not to be," quoth the bard, "that is the
question." In order to produce the desired form, the source file must
contain the sequence:

``To be or not to be,'' quoth the bard, ``that is the question.''

You are to write a program which converts text containing
double-quote (") characters into text that is identical except that
double-quotes have been replaced by the two-character sequences required
by TEX for delimiting quotations with oriented double-quotes. The
double-quote (") characters should be replaced appropriately by either
`` if the " opens a quotation and by '' if the " closes a quotation.
Notice that the question of nested quotations does not arise: The first "
must be replaced by ``, the next by '', the next by ``, the next by '',
the next by ``, the next by '', and so on.

Input

Input will consist of several lines of text containing an even number
of double-quote (") characters. Input is ended with an end-of-file
character.

Output

The text must be output exactly as it was input except that:

• the first " in each pair is replaced by two ` characters: `` and
• the second " in each pair is replaced by two ' characters: ''.

Sample Input

"To be or not to be," quoth the Bard, "that
is the question".
The programming contestant replied: "I must disagree.
To `C' or not to `C', that is The Question!"

Sample Output

``To be or not to be,'' quoth the Bard, ``that
is the question''.
The programming contestant replied: ``I must disagree.
To `C' or not to `C', that is The Question!''

---

思路：
还是得学STL，不然好多东西就是浮在表面上不能理解
这个题目也算是给解决字符串问题提供了一种思路吧，一个个的读取字符，然后再逐个的输出

---

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

int main()
{
    char c,flag = ;
    while((c=getchar())!=EOF)
    {
        if(c=='"') {
            printf("%s",flag?"``":"''");
            flag = !flag;
        }
        else
            printf("%c",c);
    }
    return ;
}