c - using qsort to sort two arrays simultaneously?

Question

I can sort a array of pointers to words so that they are ordered alphabetically, the problem is that I need to ALSO sort an integer array (the number of times that specific word is used) so that the integers are in the same place as their respective words:

my code:

for (i = 0; i < numWords; i++) {
    // prints out the words and their frequency respectively
    printf("%s - %d
", dictionary[i], frequency[i]); 
}

//sorts the dictionary so that the words are 'alphabetical'
qsort(dictionary, numWords, sizeof(char *), rstrcmp);  
printf("
after qsort
");  //checkmark

for (i = 0; i < numWords; i++) {
    // prints the word list alphabetically, but the frequencies are no longer matched
    printf("%s - %d
", dictionary[i], frequency[i]); 
}

...comparison function V

int rstrcmp(const void *p1, const void *p2) {
    return strcmp(*(char * const *)p1, *(char * const *)p2);
}

Answer 1

A simple thing to do would be to use a struct to store word/frequency pairs and then sort an array of these structs.

For example:

struct WordFrequency
{
    const char * word;
    int frequency;
} wordFreqs[numWords];        // Assumes numWords is static/global and constant...

Then:

for (i = 0; i < numWords; i++) {
    printf("%s - %d
", dictionary[i], frequency[i]);
    wordFreqs[i].word = dictionary[i];
    wordFreqs[i].frequency = frequency[i];
}

//sorts the dictionary so that the words are 'alphabetical'
qsort(wordFreqs, numWords, sizeof(struct WordFrequency), wfcmp);  

for (i = 0; i < numWords; i++) {
    printf("%s - %d
", wordFreqs[i].word, wordFreqs[i].frequency); 
}

And:

int wfcmp(const void *p1, const void *p2) {
     return strcmp(((const struct WordFrequency *)p1)->word, ((const struct WordFrequency *)p2)->word);
}