平臺：

UVa Online Judge

題號：

10037 - Bridge

題目連結：

https://onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=4&page=show_problem&problem=208

題目說明：

在TeX中，左雙引號是“``”，右雙引號是“''”。輸入一篇包含雙引號的文章，你的任務是
把它轉換成TeX的格式。

範例輸入：

"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!"

範例輸出：

``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!''

解題方法：

逐個輸入，逐個處理，直到遇到輸入結束符EOF。

程式碼：

 1 #include <cstdio>
 2 
 3 int main() {
 4     int c = ' ';
 5     //true表示第1個引號，false表示第2個引號
 

 6     bool flag = true;
 7         //(c = std::getc(stdin))!= EOF等價於(c=getchar())!=EOF
 8     while ((c = std::getc(stdin))!= EOF) {
 9         if (c == '"') {
10             if (flag) {
11                 printf("``");
12             }
13             else {
14                 printf("''");
15             }
 
16             flag = !flag;
17         }
18         else {
19             putchar(c);
20         }
21     }
22     return 0;
23 }