Answer Posted / dilip k. singh(dks)

Malloc:
1. Takes only 1 argument- the size of the memory block to
be allocated.
2. Allocates memory as a single contiguous block.
3. Will fail if a single contiguous memory block of
required size is not available.

Calloc:
1. Takes two arguments - the number of memory blocks needed
and the size of each memory block.
2. It may or may not allocate a single contiguous block,
thus will not fail if a single contiguous memory block
of required size is not available.
3. Initialises the memory blocks to 0.
sUMMARY:
malloc() allocates 1 unit(datatype) of memory each time it
is called so to allocate memory for a file read char by
char allocating memory each time for a char till EOF.
calloc allocates sizeof(datatype) bytes to the no of
elements in the file, where by the user can specify the
file size as the second arguement.
char *malloc(sizeof(datatype) )
char *calloc(sizeof(datatype), num of elements)
calloc() is more efficient as memory is allocated in 1
cycle so fewer clock cycles, more faster executiop.

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