what does program to interface means?

If the client is using functionality from your code it should be exposed to interface i.e. how to call this functionality with what parameters. It will provide an abstraction to the client and we can change the implementation anytime without impacting the caller.

Comments

Car Parking Problem

There is n parking slots and n-1 car already parked. Lets say car parked with initial arrangement and we want to make the car to be parked to some other arrangement. Lets say n = 5, inital = free, 3, 4, 1, 2 desired = 1, free, 2, 4 ,3 Give an algorithm with minimum steps needed to get desired arrangement. Told by one of my friend and after a lot of search i really got a nice solution. I will post solution in comment part

JAVA CLASSLOADER- Types, usages.

JVM loads library and classes dynamically only. Its on demand only. A Class will be loaded only when needed and only once. There can be system supported class loader and user supplied class loader. When JVM starts it loads three type of class loader 1. Bootstrap loader - When system boots. Loads from jre_home/lib/ 2. External class loader - Loads from jre_home/lib/ext. 3. System Class loader - Loads classes from system property CLASSPATH. Besides this user can provide their own class loader which is pretty easy to implement in Java. User supplied loader will work in conjunction with other loader i.e. system loader too. Some of the examples are: 1. Load library at runtime from http resources. Example scripting classes, bean classes. 2. Can load encrypted class files with new class loader. 3. Modify the byte code. Application Container loads classes from deployed WAR or EAR files using a tree of class loaders.

Permutations Sum(xi)

You have given "k" dice. How many way you can get a sum "S" and yes you have to throw all the dice. Write program for this. Its same permutations program...but we have to try with all the six S(1,2,3,4,5,6) possibilities for a dice. Exit condition will be If all the dice run out. SumP(dice,sum) = SumP(dice-1,sum-i)+i (from S).

GeeksSpot

Search This Blog