I understand what Java entails, really, OOP - Inheritance, Polymorphism.

But what annoys me is that I can't seem to solve problems with it.

Questions like the following.

i) Write a program to print the individual words and the total count of these words in a given text document without using an array or any class from the java.util package.

ii) Write a method that takes an array of non-negative integers x where x>=0 and x<101 with a duplicate value and returns that duplicate value i.e. when passed [1,2,3,9,3,3,4,1] it returns 3. It returns -1 when no duplicate is found. without using any class from java.util

iii) Write a program that accepts an array of non negative integers and returns the second highest number in that array without using any class from java.util

iv) Write a program that takes a String and returns a sorted (ascending order) array of numbers in that String and an empty array if the string contains no numbers, without using any class from java.util

Read more: http://www.justanswer.com/computer-programming/9d5oj-need-help-solving-java-exercise-relevant-methods.html#ixzz3z1XPHXWV

Anytime I see questions like this and I'm not able to solve it I just hate myself.

Or is it that I need to learn some new concepts, pls help.

The book, Java how to problem, would help.

Regards

FrankLampard:
The book, Java how to problem, would help.

Regards

I have read the book upto Recursion, its a good book though.

I can solve exercises on the book very well.

GetAvenue:


I have read the book upto Recursion, its a good book though.

I can solve exercises on the book very well.

I'll advise you work on your logical thinking. Maybe I don't understand the question. Is it that you are trying to solve the above using major OOP concepts or you just can't solve them, probably because it seems impossible ?

If you are looking just to solve them, I can easily assist with the first since that's the simplest then you can challenge yourself to do the rest

FincoApps:


I'll advise you work on your logical thinking. Maybe I don't understand the question. Is it that you are trying to solve the above using major OOP concepts or you just can't solve them, probably because it seems impossible ?

If you are looking just to solve them, I can easily assist with the first since that's the simplest then you can challenge yourself to do the rest

Thank you, I figured how to do the first. My problem is that I don't know how I can get my hands on how to use some Java inbuilt methods.

GetAvenue:


Thank you, I figured how to do the first. My problem is that I don't know how I can get my hands on how to use some Java inbuilt methods.

Methods like ?

Besides you can check for the documentation of the class that the method belongs to online

FincoApps:


Methods like ?

Besides you can check for the documentation of the class that the method belongs to online

What type of books did you read, that gave you the understanding on how to solve those kinds of questions.

[url=docs.oracle.com/javase/7/docs/api/java/util/package-summary.html]This[/url] is the summary of the java.util package. From the instructions, it seems you're supposed to develop a solution to those problems in Java, without using anything from the aforementioned package. I believe the java.util package has to first be imported before it can be used. So, the simple solution to this would be to not import it. That way, you don't run the risk of using the package.

Beyond that, honestly, it's all about critical thinking. I suggest your first step should be to always write out your algorithm by hand. Work through the algorithm with pen and paper. Then research the methods that will allow you to implement your algorithm. If it's taking too long to find the method(s) you want, then write them yourself.

GetAvenue:


What type of books did you read, that gave you the understanding on how to solve those kinds of questions.

Like Chinenyen said... It's about critical thinking. I really dislike reading except it's a documentation. What I do that enables me solve complex problems is:

I imagine I am the compiler and ask, what instructions do I need to be given in order to perform this task ?
What complex set of instructions do you give your legs in order to walk. (That's just a sample).

In your question, they basically don't want you to use Arrays, Collections, Vectors etc because they make it too easy