Sha256: a2d0a12e118e5c141e8ebf875960c15093e8930de78db4bbd939a1148ca1cab2
Contents?: true
Size: 1.27 KB
Versions: 103
Compression:
Stored size: 1.27 KB
Contents
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
class ParallelLetterFrequency {
private static Map<Integer, Integer> letterFrequencyMap;
private final String NOT_A_LETTER = "\\P{L}+";
ParallelLetterFrequency(String letters) {
letterFrequencyMap = getMapFromLetters(letters.toLowerCase().replaceAll(NOT_A_LETTER, ""));
}
Map<Integer, Integer> getMapFromLetters(String letters) {
return letters
.chars()
.parallel()
.collect(Counts::new, Counts::increment, Counts::combine)
.buildMap();
}
private static class Counts {
private Map<Integer, Integer> letterCounts = new HashMap<>();
private void increment(int letter) {
letterCounts.put(letter, letterCounts.getOrDefault(letter, 0) + 1);
}
private void combine(Counts other) {
other.letterCounts.keySet()
.forEach(letter -> letterCounts.merge(letter, other.letterCounts.get(letter), Integer::sum));
}
private Map<Integer, Integer> buildMap() {
return Collections.unmodifiableMap(letterCounts);
}
}
Map<Integer, Integer> letterCounts() {
return letterFrequencyMap;
}
}
Version data entries
103 entries across 103 versions & 1 rubygems