WA : csu1019 simple line editor

查了很多遍，不知道哪里错了，数组还不够大？

 1 # include <stdio.h>
 2 # include <ctype.h>
 3 
 4 # define MAXN 10005
 5 
 6 char a[MAXN];
 7 int i = -1, j, T;
 8 char ch;
 9 
10 int main()
11 {
12     freopen("in.txt", "r", stdin);
13     freopen("out.txt", "w", stdout);
14 
15     scanf("%d", &T);
16     getchar();
17     while (ch = getchar())
18     {
19         if (isalpha(ch)) a[++i] = ch;
20         else if (ch=='#' && i>=0) --i;
21         else if (ch == '@') i = -1;
22         else
23         {
24             for (j = 0; j <= i; ++j)
25                 putchar(a[j]);
26             putchar('\n');
27             --T;
28             if (T==0 || ch==EOF) break;
29             memset(a, 0, sizeof(a));
30             i = -1;
31         }
32     }
33 
34     return 0;
35 }