Answer from cs61c-ew (Joo-Rak Son 16103505) for Question 3
Java's equivalent of malloc is the creation of anonymous objects using "new" keyword. There is no Java's equivalent of free, because Java uses automatic memory de-allocator, aka garbage collector. C cannot use automatic memory manager because (1) in C, it is impossible to tell automatically whether a particular storage is garbage and (2) it is impossible to automatically de-allocate some space that has been allocated by the programmer. (1) is due to the fact that in C, programs can cast void pointers and pointersreturned by dynamic allocation, because it needs to know the type information of data.