Write a C program to take n files containing strings in ascending order (no duplicates within a file) and produce a file out. dat containing a line for each string (in ascending order). Even if a string str appears in multiple files, it should be output only once and, for each string, you should also output the number of files (k) containing the string. This should be done using code similar to: fprintf(outfp,"%s %d\n",str, k);