判断一个字符串是否为回文串和镜像串（Palindromes）

A regular palindrome is a string of numbers or letters that is the same forward as backward. For example, the string "ABCDEDCBA" is a palindrome because it is the same when the string is read from left to right as when the string is read from right to left.A mirrored string is a string for which when each of the elements of the string is changed to its reverse (if it has a reverse) and the string is read backwards the result is the same as the original string. For example, the string "3AIAE" is a mirrored string because "A" and "I" are their own reverses, and "3" and "E"are each others' reverses.A mirrored palindrome is a string that meets the criteria of a regular palindrome and the criteria of a mirrored string. The string "ATOYOTA" is a mirrored palindrome because if the string is read backwards, the string is the same as the original and because if each of the characters is replaced by its reverse and the result is read backwards, the result is the same as the original string. Of course, "A", "T", "O", and "Y"are all their own reverses.A list of all valid characters and their reverses is as follows.

Character	Reverse	Character	Reverse	Character	Reverse
A	A	M	M	Y	Y
B		N		Z	5
C		O	O	1	1
D		P		2	S
E	3	Q		3	E
F		R		4
G		S	2	5	Z
H	H	T	T	6
I	I	U	U	7
J	L	V	V	8	8
K		W	W	9
L	J	X	X

Note that O (zero) and 0 (the letter) are considered the same character and therefore ONLY the letter "0" is a valid character.

Input

Input consists of strings (one per line) each of which will consist of one to twenty valid characters. There will be no invalid characters in any of the strings. Your program should read to the end of file.

Output

For each input string, you should print the string starting in column 1 immediately followed by exactly one of the following strings.

STRING	CRITERIA
" -- is not a palindrome."	if the string is not a palindrome and is not a mirrored string
" -- is a regular palindrome."	if the string is a palindrome and is not a mirrored string
" -- is a mirrored string."	if the string is not a palindrome and is a mirrored string
" -- is a mirrored palindrome."	if the string is a palindrome and is a mirrored string

Note that the output line is to include the -'s and spacing exactly as shown in the table above and demonstrated in the Sample Output below.In addition, after each output line, you must print an empty line.

Sample Input

NOTAPALINDROME 
ISAPALINILAPASI 
2A3MEAS 
ATOYOTA

Sample Output

NOTAPALINDROME -- is not a palindrome.
 
ISAPALINILAPASI -- is a regular palindrome.
 
2A3MEAS -- is a mirrored string.
 
ATOYOTA -- is a mirrored palindrome.

解题报告：

这个题代码可以不用那么麻烦，回文串和镜像串可以一起判断。

先将镜像之后的字符存到一个数组里面，然后可以用字符串直接判断，类似于键盘错位那个题，这种方法大大简化了代码量，也使得变得简单。同样，输出的字符可以用一行代码就可以实现，用一个二维数组存起来所有的数。

这个代码还用到了ctype里面的一个函数，isalpha（）来判断是否是字符，同样的，还有isdigit，isprint。

如果一个字符型变量ch-‘A’，则返回的是它在字母表中的顺序，A是0，以此类推。若ch是一个数字，则ch-‘0’返回的是其数字本身，如‘5’-‘0’=5.

这种使代码简化的方法要学会，具体代码如下：

#include<cstdio>#include<cctype>#include<cstring>using namespace std;const char rev[100]="A   3  HIL JM O   2TUVWXY51SE Z  8 ";   //储存的是镜像之后的数字 //建立一个二维数组储存 const char msg[4][50]={"not a palindrome","a regular palindrome","a mirrored string","a minrrored palindrome"};char r(char ch){	if(isalpha(ch))   //ctype里面的函数 判断是否为字母 		return rev[ch-'A'];  //ch-‘A’返回值为其在字母表中的序号，A的序号是0，以此类推 	return rev[ch-'0'+25];   //是数字的情况 } int main(){	int i,j,p,m;	char s[30];	while(scanf("%s",s)==1)	{		int len=strlen(s);		p=1;		m=1;		for(i=0;i<len;i++)		{			if(s[i]!=s[len-i-1])   //不是回文串 			p=0;			if(r(s[i])!=s[len-i-1])  //不是镜像串 			m=0;		}		printf("%s -- is %s.\n\n",s,msg[m*2+p]); 	} 	return 0;}