spoj 360 Bottom Coder (Easy) 非常有趣的题目

spoj 360 Bottom Coder (Easy)

Some of you may be familiar with the TopCoder (TM) contest. Its exact rules are not important for this problem, but know that the most important part of it is writing a program according to the given specification. Many times the contestant ends up with a program which would work perfectly – if only he could change a couple of characters (like, replacing "=" by "==" in C, etc.). Unfortunately, even the best programmers sometimes aren't able to spot these tiny but necessary changes until it's too late... and that's why we developed a brand-new BottomCoder training for them!

The idea is very simple – you're given a problem specification, a source code, and a list of permitted modifications. Your task is to find a modification which would cause the program to behave according to the specification. 

Specification: "Write a program which outputs EXACTLY 42 asterisks and NOTHING more (e.g. NO end-of-line markers, like "\n", ...)" 

The code you are supposed to modify:

int i, n=42;main() {  for(i=0; i<n; i--) {    printf("*");  }}

As this is a really, really simple problem, you are only permitted to make exactly ONE of these modifications to the source: 1) Add one character to the source. 2) Delete one character from the source. 3) Replace one character in the source by a different one. 

Moreover, it would be definitely too easy if we asked you to find just one solution, so you'll need to find TWO DIFFERENT solutions in order to obtain credit for this problem. (There are exactly three different solutions, so don't worry, it can be done!) 

Input

There is no input for given problem.

Output

Your submission should consist of two parts. The first part should contain the first of your solutions. A single line with the letter "Q" follows. (Note that the letter Q is used as a separator. You will have to do without inserting the letter Q in at least one of your solutions :) After this line you should add your second solution. 

You don't need to worry much about the exact formatting of your submission. The exact judging procedure will look as follows: 

The first occurrence of the letter Q is found, the input is split into two parts. Any whitespace in each of the parts is removed. It is checked whether the two submissions differ and whether each of them was obtained from the original program by an allowed change. Each of your two submissions is compared to each of the three correct solutions.

Example

Output:int i, n=42; main(){ for(i=0; i<n; i--)   { printf("?"); } }Qint i, n=41; main() { for(i=0; i<n;i--) { printf("*"); } }

(syntactically valid (but incorrect) submission)

题目给定了一个程序，这个程序的功能是要打印出来42个星号，但是，这个程序写错了，需要我们改过来。

每次修改只能执行下边三种操作的一种：1）在源文件中添加一个字符；2）从源文件中删除一个字符；3）将源文件中的某个字符替换为其他字符。

要求只执行依次修改得到要求的程序。这个题目没有输入，输出是两个解，这两个解不能一样。题目上说这个题目只有三种解法。

下面是解法：

添加一个字符：

int i,n=42;main(){for(i=0;-i<n;i--) {printf("*");}}

修改一个字符，有两种：

int i,n=42;main(){for(i=0;i<n;n--) {printf("*");}}

int i,n=42;main(){for(i=0;i+n;i--) {printf("*");}}

应该是删除一个字符无论如何也得不到解的，三种解法就是以上的三种。这个题目思路很巧妙。值得收藏。不过它的代码风格不太好。不要学。