Compare letters permutations to dictionary C

Question

I've been trying to work on a program that outputs only the existing words of all the possible permutations of n letters, for example:

Input "eta"

Output "tea, eat, ate"

As you can notice i don't want all the other permutations that are not words, such as "aet, tae"

For this purpose i have a dictionary.txt

I already have a function that prints all the possible permutations.

On the other hand i have a piece of code that compares a string with each line of my dictionary, and prints it if there's a match.

I just cannot manage to make both work together

void swap(char *x, char *y)
{
    char temp;
    temp = *x;
    *x = *y;
    *y = temp;
}

void permute(char *a, int l, int r)
{
  int encontrado=0;
  int i;

   if (l == r)
   {
      puts (a);
   }
   else
   {
      for (i = l; i <= r; i++)
      {
         swap((a+l), (a+i));
         permute(a, l+1, r);
         swap((a+l), (a+i)); //backtrack
      }
   }
}   


int main()
{
    char str[60];
    char str_mio[] = "aet";
    int encontrado=0;
    int n = strlen(str_mio);
    permute(str_mio, 0, n-1);

    FILE *fp;

    fp = fopen("English.txt" , "r");
    if(fp == NULL) {
        perror("Error opening file");
        return(-1);
    }
    else{
        while( fgets (str, sizeof(str_mio), fp)!=NULL && encontrado!=1) {
            //puts(str);
            if(!strcmp(str,str_mio)){
                puts(str_mio);
                encontrado=1;
            }
        }
    }
    fclose(fp);

    return 0;
}

Answer 1

Your permute() routine outputs the string by directly calling puts(). Instead, you only want to output it if it's a match.

Suppose you were to refactor the dictionary check code out of main() into a new routine printIfMatch(char *str_check) where str_check takes the place of your current use of str_mio in the code in main()

Then you'd be able to call that routine from permute()