se.kth.id1020.DoublingRatio.java Source code

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Here is the source code for se.kth.id1020.DoublingRatio.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 se.kth.id1020;

import com.google.common.collect.Sets;
import com.google.common.primitives.Ints;
import edu.princeton.cs.algs4.Stopwatch;
import edu.princeton.cs.introcs.StdRandom;

import java.util.Set;

public class DoublingRatio {

    private interface SumHandler {
        int count(int[] a);
    }

    private static double timeTrial(int N, SumHandler handler) {
        int MAX = 10000000;
        Set<Integer> numbers = Sets.newHashSetWithExpectedSize(N);
        while (numbers.size() < N) {
            numbers.add(StdRandom.uniform(-MAX, MAX));
        }
        Stopwatch timer = new Stopwatch();
        int cnt = handler.count(Ints.toArray(numbers));
        return timer.elapsedTime();
    }

    public static double timeTrialTwoSum(int N) {
        return timeTrial(N, new SumHandler() {
            @Override
            public int count(int[] a) {
                return TwoSum.count(a);
            }
        });
    }

    public static double timeTrialTwoSumFast(int N) {
        return timeTrial(N, new SumHandler() {
            @Override
            public int count(int[] a) {
                return TwoSumFast.count(a);
            }
        });
    }

    public static double timeTrialThreeSum(int N) {
        return timeTrial(N, new SumHandler() {
            @Override
            public int count(int[] a) {
                return ThreeSum.count(a);
            }
        });
    }

    public static double timeTrialThreeSumFast(int N) {
        return timeTrial(N, new SumHandler() {
            @Override
            public int count(int[] a) {
                return ThreeSumFast.count(a);
            }
        });
    }

}