Design a C function that receives four input arguments and returns a void *
output value. The last three inputs are to be void * values, which need to be
cast to the appropriate typed pointers and then de-referenced within the
function to access three stored values. The first input is to be an integer
value that specifies the input pointer type as follows: the value 1 specifies
char *, 2 specifies int *, and 3 specifies double *. If the first
input is not a valid value, or if any of the three pointer inputs is NULL,
then the output value is to be NULL; otherwise, the output value is to be a
void * that points to the base address location that contains the middlemost
value of the three values pointed to by the three input pointers. If two or
three of the memory referenced locations contain the same value, then the
return pointer points to any one of those locations.