I get the following error from CodeGym, and I don't understand why??
package com.codegym.task.task10.task1012;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
/*
Number of letters
*/
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
// Alphabet
String abc = "abcdefghijklmnopqrstuvwxyz";
char[] abcArray = abc.toCharArray();
ArrayList<Character> alphabet = new ArrayList<>();
for (char letter : abcArray) {
alphabet.add(letter);
}
// Read in strings
ArrayList<String> list = new ArrayList<>();
for (int i = 0; i < 10; i++) {
String s = reader.readLine();
list.add(s.toLowerCase());
}
// write your code here
HashMap<String, Integer> countMap = new HashMap<>();
for (char letter : alphabet) {
countMap.put(Character.toString(letter), 0);
}
for (String word : list) {
for (char letter : alphabet) {
String bogstav = Character.toString(letter);
if (word.contains(Character.toString(letter))) {
if (countMap.containsKey(bogstav)) {
countMap.put(bogstav, countMap.get(bogstav) + 1);
} else {
countMap.put(bogstav, 1);
}
}
}
}
Iterator<HashMap.Entry<String, Integer>> iterator = countMap.entrySet().iterator();
while (iterator.hasNext()) {
HashMap.Entry<String, Integer> pair = iterator.next();
System.out.println(pair.getKey() + " " + pair.getValue());
}
}
}