Palindromes--uva401

problem link

https://vjudge.net/problem/UVA-401

analysis

这道题的技巧很好，很喜欢，感觉能学到蛮多东西

code

#include<cstdio>
#include<cstring>
#include<cctype>
const char* rev = "A 3 HIL JM O 2TUVWXY51SE Z 8 ";
const char* msg[] = {"is not a palindrome.",
                    "is a regular palindrome.",
                    "is a mirrored string.",
                    "is a mirrored palindrome."};

    char r(char c)
    {
        if(isalpha(c)) //是否为字母
        {
            return rev[c - 'A'];
        }
        return rev[c-'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*2<len+1; ++i)
        {
            if(s[i] != s[len-1-i])
                p = 0; //不是回文串
            if(s[i] != r(s[len-1-i]))
                m = 0;  //不是镜像串
        }
        printf("%s -- %s\n\n",s,msg[m*2+p]); //哈哈小技巧
    }
    return 0;
}