public void test() {
// The string to test.
String s = "launch at noon";
// Count them.
Map<Character, Integer> characterCounts = countCharacters(s);
// Print the results.
for (Map.Entry<Character, Integer> e : characterCounts.entrySet()) {
int count = e.getValue();
// Work out the name for the number.
String number = count < specials.length
// The special short ones.
? specials[count]
// Is it a general one?
: count < numbersAsWords.length
// Yes
? numbersAsWords[count] + " times"
// Way too many.
: "too many times";
// Print it.
System.out.println("\"" + e.getKey() + "\" appears " + number + " in \"" + s + "\".");
}
}
private Map<Character, Integer> countCharacters(String s) {
// Map from character in string to count of occurrences.
Map<Character, Integer> counts = new HashMap<>();
// Walk the string.
for (int i = 0; i < s.length(); i++) {
// Get character at that point.
char ch = s.charAt(i);
// What's in the map for that character.
Integer count = counts.get(ch);
if (count == null) {
// Not seen this character before - start at zero.
count = 0;
}
// Increment seen count.
count += 1;
// Put it back in the map.
counts.put(ch, count);
}
return counts;
}
// The short ones.
private static final String[] specials = {"not at all", "once", "twice"};
// The rest.
private static final String[] numbersAsWords = {"zero",
"one",
"two",
"three",
"four",
"five",
"six",
"seven",
"eight",
"nine",
"ten",
"eleven",
"twelve",
"thirteen",
"fourteen",
"fifteen",
"sixteen",
"seventeen",
"eighteen",
"nineteen",
"twenty",
"twenty-one",
"twenty-two",
"twenty-three",
"twenty-four",
"twenty-five",
"twenty-six",
"twenty-seven",
"twenty-eight",
"twenty-nine",
"thirty",
"thirty-one",
"thirty-two",
"thirty-three",
"thirty-four",
"thirty-five",
"thirty-six",
"thirty-seven",
"thirty-eight",
"thirty-nine",
"forty",
"forty-one",
"forty-two",
"forty-three",
"forty-four",
"forty-five",
"forty-six",
"forty-seven",
"forty-eight",
"forty-nine",
"fifty",
"fifty-one",
"fifty-two",
"fifty-three",
"fifty-four",
"fifty-five",
"fifty-six",
"fifty-seven",
"fifty-eight",
"fifty-nine",
"sixty",
"sixty-one",
"sixty-two",
"sixty-three",
"sixty-four",
"sixty-five",
"sixty-six",
"sixty-seven",
"sixty-eight",
"sixty-nine",
"seventy",
"seventy-one",
"seventy-two",
"seventy-three",
"seventy-four",
"seventy-five",
"seventy-six",
"seventy-seven",
"seventy-eight",
"seventy-nine",
"eighty",
"eighty-one",
"eighty-two",
"eighty-three",
"eighty-four",
"eighty-five",
"eighty-six",
"eighty-seven",
"eighty-eight",
"eighty-nine",
"ninety",
"ninety-one",
"ninety-two",
"ninety-three",
"ninety-four",
"ninety-five",
"ninety-six",
"ninety-seven",
"ninety-eight",
"ninety-nine",
"one hundred",
};