UVa OJ 401题（回文词）请帮我看下这段无辜的代码为什么老是runtime error！

[深蓝色的猫]

原题地址：
https://forum.csdn.net/PointForum/ui/scripts/csdn/Plugin/001/face/16.gif][/img]http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=342

原题：
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.
以下是我写的代码，对不对姑且不论，就是总是Runtime Error！求大神解答！！！
#include <stdio.h>
#include <string.h>
#include<ctype.h>
int num(char p);
char s[1000000]="";
int main(void)
{
int i;
int a[36]={0};
a[1]=1;a[8]=8;a[9]=9;a[13]=13;a[15]=15;a[20] =20;a[21]=21;a[22]=22;a[23]=23;a[24]=24;a[25]=25;a[27]=27;a[34]=34;
a[5]=29;a[10]=12;a[12]=10;a[19]=28;a[26]=31;a[28]=19;a[29]=5;a[31]=26;
while(fgets(s,1000000,stdin)!=NULL)
{
int m=1,p=1,len;
len=strlen(s)-1;s[len]='\0';
for(i=0;i<len/2;i++)
{
if(s[i]!=s[len-i-1])
{
p=0;
if(a[num(s[i])]!=num(s[len-i-1])){ m=0;break;}
}
else if(a[num(s[i])]!=num(s[len-i-1])) {m=0;break;}

}
if((len%2==1)&&(!a[num(len/2)])) m=0;

if(!m)
{
if(!p) printf("%s -- is not a palindrome.\n\n",s);
else printf("%s -- is a regular palindrome.\n\n",s);
}
else
{
if(!p)printf("%s -- is a mirrored string.\n\n",s);
else printf("%s -- is a mirrored palindrome.\n\n",s);
}
}
return 0;
}
int num(char p)
{
if(isalpha(p)) return p-'A'+1;
if(isdigit(p)) return p-'0'+26;
}

[深蓝色的猫]

引用 6 楼 northwesternwind 的回复:

num的参数有问题： C/C++ code?1if((len%2==1)&&(!a[num(len/2)])) m=0;

我爱你~AC了！真的是这个错误，改了后一下AC！ 我怎么给你分啊？

[northwesternwind]

引用 7 楼 mrxy56 的回复:

引用 6 楼 northwesternwind 的回复:num的参数有问题： C/C++ code?1if((len%2==1)&amp;&amp;(!a[num(len/2)])) m=0; 我爱你~AC了！真的是这个错误，改了后一下AC！ 我怎么给你分啊？

结贴嘛。。。。。。。。。。。

[c1997sdn]

运行了一下，没报错啊

[seadragon4ever]

看的好长啊

#include <stdio.h>
 #include <string.h>
 #include<ctype.h>
 int num(char p);
 char s[1000000]="";
 int main(void)
 {
     int i;
     int a[36]={0};
      a[1]=1;a[8]=8;a[9]=9;a[13]=13;a[15]=15;a[20] =20;a[21]=21;a[22]=22;a[23]=23;a[24]=24;a[25]=25;a[27]=27;a[34]=34;
      a[5]=29;a[10]=12;a[12]=10;a[19]=28;a[26]=31;a[28]=19;a[29]=5;a[31]=26;
     while(fgets(s,1000000,stdin)!=NULL)
     {
           int m=1,p=1,len;
           len=strlen(s)-1;s[len]='\0';
                 for(i=0;i<len/2;i++)
                      {
                          if(s[i]!=s[len-i-1])
                                  {
                                      p=0;
                                      if(a[num(s[i])]!=num(s[len-i-1])){ m=0;break;}
                                  }
                          else if(a[num(s[i])]!=num(s[len-i-1])) {m=0;break;}
 
                     }
                 if((len%2==1)&&(!a[num(len/2)])) m=0;
 
                    if(!m)
                        {
                            if(!p) printf("%s -- is not a palindrome.\n\n",s);
                            else printf("%s -- is a regular palindrome.\n\n",s);
                        }
                        else
                        {
                            if(!p)printf("%s -- is a mirrored string.\n\n",s);
                            else printf("%s -- is a mirrored palindrome.\n\n",s);
                        }
         }
         return 0;
 }
 int num(char p)
 {
     if(isalpha(p)) return p-'A'+1;
     if(isdigit(p)) return p-'0'+26;
 } 

编译没错

[northwesternwind]

num函数问题太多。 1. 小写字母处理不对 2. 既不是字母也不是数字，返回值没有设置

[深蓝色的猫]

引用 3 楼 northwesternwind 的回复:

num函数问题太多。 1. 小写字母处理不对 2. 既不是字母也不是数字，返回值没有设置

题目中有这段话，我理解的是不会有小写字母和非字母数字的情况。 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.

[深蓝色的猫]

引用 1 楼 c1997sdn 的回复:

运行了一下，没报错啊

一交到网上就Runtime Error，邪门了

[northwesternwind]

num的参数有问题：

if((len%2==1)&&(!a[num(len/2)])) m=0;