Thread: Help with array of Strings...Linear Search?

Hello everyone,

I've recently been introduced to arrays in my java module and i'm stuck on a question:

Write a program which reads a sequence of words, and prints a count of the number of distinct words. An example of input/output is

should I stay or should I go
5 distinct words

Could anybody explain to me how I would go about checking the array to see if each word has occurred already? Is linear searching the best route to take? Thanks for any help given. Oh and class Console is just a more convenient version of ConsoleReader()

Even though this is probably all wrong, here is my attempted code so far:

 
public class DistinctWords
{	
	public static void main(String[] args)
	{
		String[] words = new String[10]; // Allow up to 10 words 	
		int count=0;
		int distinctWord=0;
		System.out.println("Enter sentence:");
		while(!Console.endOfFile())
		{
			words[count]=Console.readToken();
			count++;
		}
                int i=1;
		while(i<count && !words[i].equals(words[i-1]))
		{
			i++;
		}
		if(i<count) // found
			System.out.println("Found");
	}//end main
}//end class

A Map or Set would be perfect for this, but perhaps not the purpose of the question. There are many ways to go about doing this. Write out the problem by hand - you have an array you'd like to loop over to check for duplicates, how would you do this?

Break the problem down to the basics - you need something to loop, something to check equality, something to count - but one thing at a time...write it down, and look at it visually (often time helps). You've got an array

0 1 2 3 4 5 6 7 8 9


10 elements in the array. How would you iterate over this array? How would you check things are equal? Once you've got that down, how would you count (how about create a new class that contains the string and count)?