输入多行字符判断是否是回文 求教

Bart’s Palindromes
Time Limit: 1000ms, Special Time Limit:2500ms, Memory Limit:32768KB
Total submit users: 77, Accepted users: 61
Problem 11498 : No special judgement
Problem description
Bart is trying to come up with funny palindromes, and decides to write a program to check whether a string is a palindrome. The program should read strings on separate lines and determine whether the entire string is a palindrome. The program should only check letters (i.e., a-z, A-Z), and ignore all blanks, numbers, and punctuation.




Input
The input will consist of a sequence of lines, each of which should be tested separately. Each line will be no greater than 100 characters long. A blank line signals the end of input.


Output
After each line, the program should print on a separate line, either YES (if the input was a palindrome) or NO (otherwise).


Sample Input
radar
rAd. Ar
radiar
able was I ere I saw elba!
b
bb
ab
aabaa
aabbaa
aab2aa
aabaaa
This is a palindrome
radar is a palindrome
a man, a plan, a canal, panama!
a bell was eye, ear I saw elbow
go hang a salami, bub, i’m a lasagna hog!!

Sample Output
YES
YES
NO
YES
YES
YES
NO
YES
YES
YES
NO
NO
NO
YES
NO
YES

# include<stdio.h>

# include<stdlib.h>

# include<string.h>

# include<ctype.h>

int main()

{

    

    char *str1,str[1000] = {NULL};

    char *str2;

    char c;

    int i,j;

    //freopen("outt.txt","w",stdout);

    while(1)

    {

        str2 = (char*)calloc(1000,sizeof(char));

        str1 = (char*)calloc(1000,sizeof(char));

        i =0;

        while((c = getchar())!= '\n')

        {

            if(isalpha(c))

                str1[i++] = c;

            if(c == EOF)

                return 1;

        }

        str1[i] = '\0';

        memcpy(str2,str1,strlen(str1));

        strrev(str1);

        if(strcmp(str1,str2))

            printf("NO\n");

        else

            printf("YES\n");



        free(str1);

        str1 = NULL;

        free(str2);

        str2 = NULL;

    }

        

    return 0;

}

不知道我的程序错在哪 提交的时候 runtime 错误 是不是结束没有处理好文件的结束符 题目地址 http://acm.hnu.cn:8080/online/?action=problem&type=show&id=11498&courseid=131