CODEWITHSUNDEEP
javadata-structures
Wael Showair
Wael Showair

Reputation: 3102

Appropriate data structure for int, int & string

I am hesitating what is the suitable data structure to save the following data form:

  1. an integer represents min number
  2. an integer represents max number
  3. a string contains a message

So that if I have a result_number I can -

  1. check if result_number lies between the min & max number
  2. and display the corresponding message

So what is the appropriate data structure?

Upvotes: 1

Views: 2461

Answers (3)

Sergey Kalinichenko
Sergey Kalinichenko

Reputation: 726639

If the number of intervals is small, use a class with three members (min, max, and message), store them in a list, and run a linear search.

If the number of intervals is overwhelming, and the timing requirements make linear search prohibitive, create an interval tree, ans associate the messages with its leaf nodes.

If the intervals are not overlapping, you can create an interval class with two ends, and store interval objects in a TreeMap using their left boundary to compare intervals. With this TreeMap in hand, you can find an interval quickly by calling floorEntry on the number that you are trying to locate and checking if the returned interval key overlaps the value that you are looking for.

Upvotes: 2

Jon Skeet
Jon Skeet

Reputation: 1500875

It sounds like you want...

(Wait for it...)

... a class with two integers and a string.

public final class RangeValidation {
    private final int minimum;
    private final int maximum;
    private final String message;

    public RangeValidation(int minimum, int maximum, String message) {
        if (minimum > maximum) {
            throw new IllegalArgumentException("Invalid min/max combination");
        }
        if (message == null) {
            throw new NullPointerException();
        }
        this.minimum = minimum;
        this.maximum = maximum;
        this.message = message;
    }

    // You can tweak this API, of course...
    // it could throw an exception instead, or return an empty string for
    // success, etc.
    public String validate(int value) {
        return value < minimum || value > maximum ? mesasge : null;
    }
}

Of course you may want to make this implement an interface to fit in with a more general validation framework etc... but the important point is that you've already neatly describe what you want your type to contain - so you just need to write it.

Also note that this counts the maximum value as inclusive - you may wish to make it exclusive, in order to be able to represent empty ranges. (That does make it harder to represent a range for which Integer.MAX_VALUE is valid though...)

Upvotes: 7

Bohemian
Bohemian

Reputation: 425073

In java a "data structure" is represented by a class with fields. The class may have methods that use these fields.

Try this:

public class MyClass {

    private int min;
    private int max;
    private String message;

    public void testNumber(int number) {
        if (number >= min && number <= max) {
            System.out.println(message);
        }
    } 
}

You should probably have a constructor to set the values of the fields and I would recommend making the fields final.

Upvotes: 3

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