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/*
* 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.util.concurrent.ConcurrentSkipListMap;
import java.util.concurrent.ConcurrentMap;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.stream.Stream;
public class CalculateAverage_ivanklaric {
private static final String FILE = "measurements.txt";
record CityTemps (double min, double max, double sum, long count) {
public String toString() {
return round(min) + "/" + round(sum / count) + "/" + round(max);
}
private double round(double num) {
return Math.round(num * 10.0) / 10.0;
}
}
public static void main(String[] args) throws IOException {
Stream<String> lines = Files.lines(Paths.get(FILE));
ConcurrentMap<String, CityTemps> cityStats = new ConcurrentSkipListMap<>();
lines.parallel().forEach(line -> {
int splitterLoc = line.indexOf(';');
double temp = Double.parseDouble(line.substring(splitterLoc + 1, line.length()));
cityStats.merge(line.substring(0, splitterLoc), new CityTemps(temp, temp, temp, 1),
(oldValue, defaultValue) -> {
return new CityTemps(Math.min(oldValue.min, temp), Math.max(oldValue.max, temp), oldValue.sum + temp, oldValue.count + 1);
});
});
System.out.println(cityStats);
}
}
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