11. Most Frequent Word

/* Write a program to find the most frequent word in a text and print it,
 * as well as how many times it appears in format "word -> count".
 * Consider any non-letter character as a word separator.
 * Ignore the character casing. If several words have the same maximal frequency,
 * print all of them in alphabetical order. */

import java.util.ArrayList;
import java.util.Scanner;
import java.util.TreeMap;

public class _11_MostFrequentWord {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner scan = new Scanner(System.in);
        System.out.println("Enter your text on single line:");
        String inputLine = scan.nextLine().toLowerCase();

        String[] text = inputLine.split("[^a-z]+");
        TreeMap<String, Integer> frequentWords = new TreeMap<>();
        for (String string : text) {
            Integer times = frequentWords.get(string);
            if (times == null) {
                times = 0;
            }

            frequentWords.put(string, times + 1);
        }

        ArrayList<String> mostFrequentWords = new ArrayList<>();
        int maxTimesAppears = 1;
        for (String key : frequentWords.keySet()) {
            if (frequentWords.get(key) > maxTimesAppears) {
                maxTimesAppears = frequentWords.get(key);
                mostFrequentWords = new ArrayList<>();
                mostFrequentWords.add(key);
            } else if (frequentWords.get(key) == maxTimesAppears) {
                mostFrequentWords.add(key);
            }
        }

        for (String word : mostFrequentWords) {
            System.out.println(word + " -> " + frequentWords.get(word)
                    + " times");
        }
    }

}