85fa0891bc
Execution time: 1 minute and 27.863 seconds System specs: Apple M1, 8 cores, 16GB RAM Co-authored-by: santanu barua <santanu@host109.private.net>
63 lines
2.5 KiB
Java
63 lines
2.5 KiB
Java
/*
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* Copyright 2023 The original authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package dev.morling.onebrc;
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import java.io.IOException;
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import java.nio.file.Files;
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import java.nio.file.Path;
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import java.util.DoubleSummaryStatistics;
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import java.util.Map;
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import java.util.function.Function;
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import java.util.stream.Collectors;
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import static java.lang.Double.parseDouble;
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import static java.lang.String.format;
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import static java.util.stream.Collectors.summarizingDouble;
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public class CalculateAverage_santanu {
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private static final String DATA_FILE = "./measurements.txt";
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private static final String PRINT_FORMAT = "%s=%.1f/%.1f/%.1f";
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public static void main(String[] args) throws IOException {
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Map<String, DoubleSummaryStatistics> summaryStatisticsMap = processMeasurements();
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printResults(summaryStatisticsMap);
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}
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private static final Function<String, StationMeasurementPair> stationMeasurements = row -> {
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int splitPosition = row.indexOf(";");
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return new StationMeasurementPair(row.substring(0, splitPosition), parseDouble(row.substring(splitPosition + 1)));
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};
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private static Map<String, DoubleSummaryStatistics> processMeasurements() throws IOException {
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return Files.lines(Path.of(DATA_FILE)).map(stationMeasurements).parallel()
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.collect(Collectors.groupingBy(
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StationMeasurementPair::station, summarizingDouble(StationMeasurementPair::measurement)));
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}
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private static void printResults(Map<String, DoubleSummaryStatistics> collect) {
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String result = collect.entrySet().parallelStream().sorted(Map.Entry.comparingByKey()).map(s -> format(PRINT_FORMAT, s.getKey(),
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s.getValue().getMin(), s.getValue().getAverage(), s.getValue().getMax())).collect(Collectors.joining(", "));
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System.out.println("{" + result + "}");
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}
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private record StationMeasurementPair(String station, Double measurement) {
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}
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}
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