POJ 1590 Palindromes 肯爹题

本题就是专门肯人的题目，给出的列子也是故意误导人的。

其实就考一点：没有mirror的字母存在的时候就可以判定整个字符串不是mirror！

如下面的mirrored string的叙述：

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. 

愣是没说没有mirror的时候如何判断，要自己猜测。

题意重要，聪明地判断题意也很重要。高端人才，各种陷阱，各种细节都要考虑到极致了。

本来找Palindrome的题目做做，看到这么简单本来不想做的，花了几分钟敲出代码来，居然WA，没想到也学到东西了。不能小看任何所谓“水”题啊。

#include <stdio.h>#include <vector>#include <string.h>#include <algorithm>#include <iostream>#include <string>#include <limits.h>#include <stack>#include <queue>#include <set>#include <map>using namespace std;bool mirror, palin;char tbl[256];void initTable(){memset(tbl, 0, sizeof(tbl));tbl['A'] = 'A';tbl['E'] = '3';tbl['H'] = 'H';tbl['I'] = 'I';tbl['J'] = 'L';tbl['L'] = 'J';tbl['S'] = '2';tbl['M'] = 'M';tbl['O'] = 'O';tbl['T'] = 'T';tbl['U'] = 'U';tbl['V'] = 'V';tbl['W'] = 'W';tbl['X'] = 'X';tbl['Y'] = 'Y';tbl['1'] = '1';tbl['Z'] = '5';tbl['2'] = 'S';tbl['3'] = 'E';tbl['5'] = 'Z';tbl['8'] = '8';}void getPalinMirror(string &s){palin = true;for (int i = 0, j = (int)s.size()-1; i < j && palin; i++, j--){if (s[i] != s[j]) palin = false;}mirror = true;for (int i = 0, j = (int)s.size()-1; i <= j && mirror; i++, j--){if (!tbl[s[i]] || s[i] != tbl[s[j]]) mirror = false;}}int main(){string s;initTable();while (cin>>s){getPalinMirror(s);printf("%s", s.c_str());if (!palin && !mirror) puts(" -- is not a palindrome.");else if (palin && !mirror) puts(" -- is a regular palindrome.");else if (!palin && mirror) puts(" -- is a mirrored string.");else if (palin && mirror) puts(" -- is a mirrored palindrome.");putchar('\n');}return 0;}