POJ1488 UVA272 UVALive5381 TEX Quotes【輸入輸出+水題】_POJ1488

TEX Quotes Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 10850   Accepted: 5630

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which converts text containing double-quote (") characters into text that is identical except that double-quotes have been replaced by the two-character sequences required by TEX for delimiting quotations with oriented double-quotes.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, "thatis 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, ``thatis the question''.The programming contestant replied: ``I must disagree.To `C' or not to `C', that is The Question!''

Source East Central North America 1994

Regionals 1994 >> North America - East Central NA

問題連結：POJ1488 UVA272 UVALive5381 TEX Quotes。

問題簡述：參見上文。

問題分析：這是一個有關字元流處理的問題，也是一個引號轉換的問題。

程式說明：程式中，使用標誌變數flag來識別開始引號還是結束引號。

AC的C語言程式如下：

/* POJ1488 UVA272 UVALive5381 TEX Quotes */#include <stdio.h>int main(void){    int c, flag = 1;    while((c=getchar()) != EOF) {        if(c == '"') {            if(flag) {                putchar('`');                putchar('`');            } else {                putchar('\'');                putchar('\'');            }            flag = 1 - flag;        } else            putchar(c);    }    return 0;}