string array where the number of rows is input by user in C

This link may help

Pointers can be easily used to create a 2D array in C using malloc. The idea is to first create a one dimensional array of pointers, and then, for each array entry, create another one dimensional array.

Another answer is present in the stack overflow it self malloc() for a 2D array (using pointer-to-pointer)

If you want to index the array using two subscripts words[i][j], then you need to do two allocations (well, you could make it one if you're really confident in your handling of pointers, but you'd do better with two if you're asking this question).

You need to allocate enough space for the pointers, and enough space for the data:

char **words = malloc(wordCount * sizeof(*words));
char  *data  = malloc(wordCount * MAX_WORD_LENGTH);

if (words == 0 || data == 0)
{
    free(data);
    free(words);
    ...report error?...
}

for (int i = 0; i < wordCount; i++)
    words[i] = data + (i * MAX_WORD_LENGTH);

...now you can use words[i][j] to access the jth character of the ith word...

If you want to have user defined size for each word pointer in the words array :

char * words[wordCount];
for (i =0; i< wordCount; i++)
words[i] = malloc(sizeof(char)*User_defined_Size);

char **words = NULL;
words = (char **)malloc(sizeof(char*) * user_defined_size_A);
for(i = 0; i < user_defined_size_A; i++) {
   words[i] = (char*) malloc(sizeof(char) * user_defined_size_B);
}

you can try this...