POJ 1035 Spell checker

# include <stdio.h>
# include <string.h>

# define WL 17

int n;
char dic[10005][WL], word[WL];

char exist(char *buf)
{
int i;

for (i = 0; i < n; ++i)
{
if (strcmp(dic[i], word) == 0) return 1;
}

return 0;
}

char replace(char *x, char *y)
{
int i, lenx, leny, cnt;

lenx = strlen(x), leny = strlen(y);
if (lenx != leny) return 0;
for (cnt = 0, i = 0; i < lenx; ++i)
{
if (x[i] != y[i]) ++cnt;
if (cnt > 1) return 0;
}
return 1;
}

char add(char *x, char *y)
{
int i, j, lenx, leny, cnt;

lenx = strlen(x), leny = strlen(y);
if (leny != lenx+1) return 0;
for (cnt = 0, i = 0, j = 0; i < leny; ++i, ++j)
{
if (x[i] != y[j]) ++cnt, --i;
if (cnt > 1) return 0;
}
return 1;
}

void find(char *buf)
{
int i;

printf(":");
for (i = 0; i < n; ++i)
{
if (replace(dic[i], buf) || add(buf, dic[i]) || add(dic[i], buf))
printf(" %s", dic[i]);
}
}

int main()
{
for (n = 0; scanf("%s", dic
), dic
[0] != '#'; ++n) ;
for ( ; scanf("%s", word), word[0] != '#'; )
{
printf("%s", word);
if (exist(word)) printf(" is correct");
else find(word);
putchar('\n');
}

return 0;
}