62 lines
2.3 KiB
Java
62 lines
2.3 KiB
Java
/*
|
|
* Copyright 2023 The original authors
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
package dev.morling.onebrc;
|
|
|
|
import java.io.IOException;
|
|
import java.nio.file.Files;
|
|
import java.nio.file.Path;
|
|
import java.util.DoubleSummaryStatistics;
|
|
import java.util.Map;
|
|
import java.util.function.Function;
|
|
import java.util.stream.Collectors;
|
|
import java.util.stream.Stream;
|
|
|
|
import static java.util.stream.Collectors.groupingBy;
|
|
|
|
public class CalculateAverage_khmarbaise {
|
|
|
|
private static final Path MEASUREMENT_FILES = Path.of("./measurements.txt");
|
|
|
|
private record MeasurementRecord(String city, Double measuredValue) {
|
|
}
|
|
|
|
private static final Function<String, MeasurementRecord> toMeasurementRecord = line -> {
|
|
var posOf = line.indexOf(";");
|
|
var city = line.substring(0, posOf);
|
|
var measuredValue = line.substring(posOf + 1);
|
|
return new MeasurementRecord(city, Double.parseDouble(measuredValue));
|
|
};
|
|
|
|
private static final Function<Map.Entry<String, DoubleSummaryStatistics>, String> MIN_AVG_MAX = s -> String.format("%s=%.1f/%.1f/%.1f", s.getKey(),
|
|
s.getValue().getMin(), s.getValue().getAverage(), s.getValue().getMax());
|
|
|
|
public static void main(String[] args) throws IOException {
|
|
try (Stream<String> lines = Files.lines(MEASUREMENT_FILES)) {
|
|
var collect = lines
|
|
.parallel()
|
|
.map(toMeasurementRecord)
|
|
.collect(groupingBy(MeasurementRecord::city, Collectors.summarizingDouble(MeasurementRecord::measuredValue)))
|
|
.entrySet()
|
|
.stream()
|
|
.sorted(Map.Entry.comparingByKey())
|
|
.map(MIN_AVG_MAX)
|
|
.collect(Collectors.joining(", "));
|
|
|
|
System.out.println("{" + collect + "}");
|
|
}
|
|
}
|
|
}
|