输入一个字符串，判断它是否为回文串或者镜像串.输入字符串保证不含数字0.所谓回文串，就是翻转以后和原串相同，如abba和madam。所有镜像串，就是左右镜像之后和原串相同，如2S和3AIAE。
#include<stdio.h> #include<string.h> #include<ctype.h> const char* rev = "A 3 HIL JM O 2TUVWXY51SE Z 8 "; const char* msg[] = { "not a palindrome", "a regular palindrome", "a mirrored string", "a mirrored palindrome" }; char r(char ch) //判断字符是数字还是字母 { if (isalpha(ch)) return rev[ch - 'A']; return rev[ch - '0' + 25]; } int main() { char s[30]; while (scanf("%s", s) == 1) { int len = strlen(s); int p = 1, m = 1; for (int i = 0; i < (len + 1) / 2; i++) { if (s[i] != s[len - 1 - i])p = 0;//不是回文串 if (r(s[i] != s[len - 1 - i]))m = 0;//不是镜像串 } printf("%s -- id %s.\n\n", s, msg[m * 2 + p]); } }