uva123 Searching Quickly

短小而精悍的代码，把我所学的几乎都用上了，测试数据过了，只可惜不AC，挣扎了一天了，累死啦！！！！！

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<ctype.h>
int cmp(const void *a,const void *b)
{
    return strcmpi((char *)a,(char *)b);
}
char word[210][17],iword[51][17],st[10002];
int main()
{
    int itop = 0, top = 0, i = 0, j = 0, k = 1, s[10001] = {0}, t = 0, r;
    char ch;
    while(gets(iword[itop]))
    {
        if(strcmp(iword[itop],"::") == 0)
            break;
        itop++;
    }
    while((ch = getchar()) != EOF)
    {
        t++;
        if(ch != '\n')
            st[i++] = ch;
        if(ch != ' ' && ch != '\n')
            word[top][j++] = ch;
        else
        {
            word[top][j] = '\0';
            top++;
            for(r = 0;r < itop; r++)
            {
                if(strcmpi(iword[r],word[top-1]) == 0)
                {
                    top--;
                    break;
                }
            }
            j = 0;
            if(ch == '\n')
            {
                st[i++] = '\0';
                s[k++] = t;
            }
        }
    }
    qsort(word,top,sizeof(word[0]),cmp);
    for(j = 0;j < top; j++)
    {
        int len = strlen(word[j]), x = 0;
        if(strcmpi(word[j],word[j+1]) == 0)
        {
            continue;
        }
        for(r = 0;r < k; r++)
        {
            x = 0;
            while(strstr(st+s[r]+x,word[j]) != NULL)
            {
                char *p = strstr(st+s[r]+x,word[j]), *q;
                x = p - st+len;
                for(q = st+s[r];q < p; q++)    
                {
                    if(isalpha(*q))
                        putchar(tolower(*q));
                    else
                        putchar(*q);
                    
                }
                for(;q < p+len; q++)
                    putchar(toupper(*q));
                for(;*q != '\0';q++)
                {
                    if(isalpha(*q))
                        putchar(tolower(*q));
                    else
                        putchar(*q);
                    
                }
                puts("");
            }
        }
    }
    return 0;
}