Thread: Array Histogram

Hello, I'm having trouble coding a program which reads in strings (search terms) from a file, orders them, and then creates a histogram showing the occurrence of each string length.

For example, if the search terms were: frog, cat, dog; the program would print the following output:

Search Terms
-------------
frog
cat
dog

Term Length ... Count
------------ ... ------
3 .................... 2
4 .................... 1

I have the program reading in terms and sorting them, but I can't get the histogram to display the number of occurrences for each term.

I get output like this:
3 .......... 1
3 .......... 1
4 .......... 1

I know it's a logic error, but what should I be doing?

package nicepackage;
 
import java.io.*;
import java.util.Scanner;
 
public class Search {
 
	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception {
		System.out.println("\nSearch Terms");
		System.out.print("------------");
 
		FileReader fr1 = new FileReader("C:\\users\\T\\inSearchterms.txt");
		Scanner inFr1 = new Scanner (fr1);
 
		int n = inFr1.nextInt()+1;
		String[] a = new String[n];
		for (int i=0; i<n; i++)
		{
			a[i]= inFr1.nextLine();
			//System.out.println(a[i]);
		}
		selectionSort(a);
		System.out.println("\nTerm Length	Count");
		System.out.println("-----------	-----");
 
		int[] histogram = new int[n];
		int[] ct = new int[n];
 
		for (int b=1; b <= a.length-1; b++)
		{
			for (int d = 30; d >= 0; d--)
			{
				if (d == a[b].length())
				{
					histogram[b] = a[b].length();
					ct[b]++;
				}
			}
			System.out.println(histogram[b] + "		" + ct[b]);
		}
	}
 
	public static void selectionSort (String [] a)
	{
		for (int i=a.length-1; i >= 1; i--)
		{
			String currentMax = a[0];
			int currentMaxIndex = 0;
			for (int j=1; j <= i; j++)
			{
				if (currentMax.compareToIgnoreCase(a[j])<0)
				{
					currentMax = a[j];
					currentMaxIndex = j;
				}
			}
			if (currentMaxIndex != i)
			{
				a[currentMaxIndex] = a[i];
				a[i] = currentMax;
			}
			//System.out.println("/"+a[i]);
		}
 
	}
}

What am I doing wrong? Any help is greatly appreciated, thanks!

Unfortunately, I don't know how to use a Map.

I need the program to determine the max String length, can I do that using the process you described? If I'm understanding correctly, I think that's what I'm trying to do. I set up two int arrays, one called histogram and one called ct, each with as many slots as there are terms in the file (or at least that's what I intended to do).

I know that the longest String in the file I'm using is 26 characters, but I can't just create the array specific to the Strings in this file because I need it to work with any file.

Thanks for your help so far.

I think I'm trying to use parallel arrays. Am I initializing them correctly in my code? I believe that's where I'm getting errors.

Can somebody take another look at this, please? I'm losing my mind trying to figure this out.