章三例题1 UVA 272

TEX Quotes

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

and ” 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which converts text containing double-quote (“) characters into text that is identical except that double-quotes have been replaced by the two-character sequences required by TeX for delimiting quotations with oriented double-quotes.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!”

题意，就是遇到左”,就变为“，遇到右”,就变为”(两个单引号）；

用getchar读取一个字符后判断

代码

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>

using namespace std;

int main()
{
int flag=0;
int c;
while((c=getchar())!=EOF)//这里用的是getchar然后（c=getchar()）这个括号不要掉了
{
if(c=='"'&&flag==0)
{
printf("``");
flag=1;
}
else  if(c=='"'&&flag==1)
{
printf("''");
flag=0;
}
else
printf("%c",c);
}
return 0;
}