Palindromes
Time Limit:3000MS Memory Limit:0KB 64bit IO Format:%lld
& %llu
Description
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.
Hint
use the C++‘s class of string will be convenient, but not a must
此题涉及到两种串,一种是回文串,一种是镜像串,回文串是从前向后和从后向前都是一样的,镜像串是经过上图的代换后能像回文串的串。一共有四种情况:(1)是回文串也是镜像串(2)是回文串不是镜像串(3)是镜像串不是回文串(4)不是镜像串也不是回文串。给你一个串让你判断是哪种情况。
#include <stdio.h> #include <string.h> #include <stdlib.h> #include <algorithm> using namespace std; char a[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789"; char b[]="A 3 HIL JM O 2TUVWXY51SE Z 8 "; char str[1010]; int is_p(char str[]) { int i; int len=strlen(str); for(i=0; i<(len/2); i++) { if(str[i]!=str[len-i-1]) return 0; } return 1; } int is_m(char str[]) { int i,j; int len=strlen(str); if(len==1) { for(i=0; i<35; i++) { if(str[0]==a[i]) break; } if(i==35||str[0]!=b[i]) return 0; else return 1; } else if(len>1) { for(i=0; i<(len/2+1); i++) { for(j=0; j<35; j++) { if(str[i]==a[j]) break; } if(j==35||str[len-i-1]!=b[j]) return 0; } return 1; } } int main() { int flag1,flag2; while(~scanf("%s",str)) { flag1=is_p(str); flag2=is_m(str); //printf("%d %d<<<<<<<",flag1,flag2); if(flag1&&flag2) { printf("%s -- is a mirrored palindrome.\n\n",str); } else if(flag1&&!flag2) { printf("%s -- is a regular palindrome.\n\n",str); } else if(flag2&&!flag1) { printf("%s -- is a mirrored string.\n\n",str); } else if(!flag2&&!flag1) { printf("%s -- is not a palindrome.\n\n",str); } } return 0; }