组团旅游问题优化实现

说明：算法来自于《集体智慧编程》-第五章

原书代码用 Python 实现，这两天看这章书，改用 Java 实现。

问题描述：Glass 一家六人在全国各地c，要到 LGA 碰头聚会。求花费最少的解法。

和原书代码意思不同的：计算增加了旅途中时间，0.5/h

/**
 *
 * FILENAME: Optimization.java
 * AUTHOR:   vivizhyy[at]gmail.com
 * STUID:    whu
 * DATE:     2010-4-12
 * USAGE :
 */
package ch5.optimization;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Random;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;
import org.joda.time.DateTime;
import org.joda.time.LocalTime;

public class Optimization {

    private HashMap<String, String> people = new HashMap<String, String>();
    private static String[] family = {"Seymour", "Pranny", "Zooey", "Wait", "Buddy", "Les"};
    private String destination = "LGA";
    private Flights flights = new Flights();
    private static final int MEMBER_NUM = 6;
    private Logger log = Logger.getLogger(Optimization.class.getName());

    private void initPeople() {
        this.people.put("Seymour", "BOS");
        this.people.put("Pranny", "DAL");
        this.people.put("Zooey", "CAK");
        this.people.put("Wait", "MIA");
        this.people.put("Buddy", "ORD");
        this.people.put("Les", "OMA");
    }

    /**
     * 
     * @param times
     */
    public void printSchedule(int[] times) {
        StringBuilder scheduleResult = new StringBuilder();
        int index = 0;
        for (String mem : family) {
            scheduleResult.append(mem + "\t"
                    + people.get(mem) + "\t");
            Flights f = flights.getFlightByOriginAndDest(people.get(mem), destination)[times[index * 2]];
            scheduleResult.append(f.getDepart() + "-" + f.getArraive() + "\t$"
                    + f.getPrice() + "\t");
            f = flights.getFlightByOriginAndDest(destination, people.get(mem))[times[index * 2 + 1]];
            scheduleResult.append(f.getDepart() + "-" + f.getArraive() + "\t$"
                    + f.getPrice() + "\n");

            index++;
        }

        System.out.println(scheduleResult);
    }

    /**
     * 
     * @param t
     * @return
     */
    public int getMinutes(LocalTime t) {
        return (t.getMinuteOfHour() + t.getHourOfDay() * 60);
    }

    /**
     * 
     * @param sol
     * @return
     */
    public double scheduleCost(int[] sol) {
        PropertyConfigurator.configure("D:/Documents/NetBeansProjects/CollectiveProgramming/src/log4j.properties");
        double totalPrice = 0.0;
        int lastArrival = 0;
        int earliestDep = 24 * 60;
        int totalTravel = 0;
        Flights[] outBound = new Flights[MEMBER_NUM * 2];
        Flights[] returnFlight = new Flights[MEMBER_NUM * 2];
        for (int i = 0; i < MEMBER_NUM; i++) {
            //得到往返航班
            outBound[i] = flights.getFlightByOriginAndDest(people.get(family[i]), destination)[sol[i * 2]];
            returnFlight[i] = flights.getFlightByOriginAndDest(destination, people.get(family[i]))[sol[i * 2 + 1]];

            //log.info("price:" + outBound[i].getPrice() + "\t" + returnFlight[i].getPrice());
            //加航班价格
            totalPrice += outBound[i].getPrice();
            totalPrice += returnFlight[i].getPrice();

            //加旅行时间
            totalTravel += getMinutes(outBound[i].getArraive()) - getMinutes(outBound[i].getDepart());
            totalTravel += getMinutes(returnFlight[i].getArraive()) - getMinutes(returnFlight[i].getDepart());

            //记录最晚到达时间和最早离开时间
            if (lastArrival < getMinutes(outBound[i].getArraive())) {
                lastArrival = getMinutes(outBound[i].getArraive());
            }
            if (earliestDep > getMinutes(returnFlight[i].getDepart())) {
                earliestDep = getMinutes(returnFlight[i].getDepart());
            }
        }

        int totalWait = 0;
        for (int i = 0; i < MEMBER_NUM; i++) {
            totalWait += lastArrival - getMinutes(outBound[i].getArraive());
            totalWait += getMinutes(returnFlight[i].getDepart()) - earliestDep;
        }

        //要多付一天的汽车租用金吗？
        if (lastArrival > earliestDep) {
            totalPrice += 50;
        }

        totalPrice = totalPrice + totalWait + totalTravel * 0.5;

        return totalPrice;
    }

    /**
     * 随机在 <code>loopTimes</code> 次中找出最值
     * @param loopTimes
     * @return
     */
    public int[] randomOptimize(int loopTimes) {
        int[] bestr = new int[MEMBER_NUM * 2];
        double best = 999999999;
        for (int i = 0; i < loopTimes; i++) {
            int[] r = randomResult();
            double price = scheduleCost(r);
            if (best > price) {
                best = price;
                bestr = r;
            }
        }
        System.out.println("total cost: " + best);
        return bestr;
    }

    /**
     * 爬山法
     * 
     * @return
     */
    public int[] hillclimb() {
        int[] sol = randomResult();
        double best = 999999999;
        int count = 0;
        while (true) {
            count++;
            int[][] neighbors = new int[MEMBER_NUM * 2][MEMBER_NUM * 2];
            for (int j = 0; j < MEMBER_NUM * 2; j = j + 2) {
                if (sol[j] > 0) {
                    for (int m = 0; m < MEMBER_NUM * 2; m++) {
                        if (m == j && sol[j] <= 9) {
                            neighbors[j][m] = sol[m] + 1;
                        } else {
                            neighbors[j][m] = sol[m];
                        }
                    }
                }
                if (sol[j] <= 9) {
                    for (int m = 0; m < MEMBER_NUM * 2; m++) {
                        if (m == j && sol[j] != 0) {
                            neighbors[j + 1][j] = sol[m] - 1;
                        } else {
                            neighbors[j + 1][m] = sol[m];
                        }
                    }
                }
            }

            double currentCost = scheduleCost(sol);
            for (int m = 0; m < MEMBER_NUM; m++) {
                double cost = scheduleCost(neighbors[m]);
                //System.out.println("cost: " + cost);
                if (cost < best) {
                    best = cost;
                    sol = neighbors[m];
                }
            }
            if (best == currentCost) {
                System.out.println("best: " + best);
                System.out.println("loop: " + count);
                return sol;
            }
        }
    }

    /**
     * 退火算法
     *
     * @param T
     * @param cool
     * @param step
     * @return
     */
    public int[] annealingoptimize(double T, double cool, int step) {
        int[] vec = randomResult();
        long seed = System.nanoTime();
        Random random = new Random(seed);

        while (T > 0.1) {
            int index = random.nextInt(MEMBER_NUM * 2 - 1);
            int dir = (int) (random.nextInt(step) * Math.pow(-1, random.nextInt()));
            // System.out.println("dir: " + dir);
            int[] vecb = new int[MEMBER_NUM * 2];

            for (int i = 0; i < MEMBER_NUM * 2; i++) {
                if (i == index) {
                    if (vec[i] + dir < 0) {
                        vecb[i] = 0;
                        continue;
                    }
                    if (vecb[i] > 9) {
                        vecb[i] = 9;
                        continue;
                    }
                    vecb[i] = vec[i] + dir;
                } else {
                    vecb[i] = vec[i];
                }
            }

            double ea = scheduleCost(vec);
            double eb = scheduleCost(vecb);
            if (eb < ea || random.nextDouble() < Math.pow(Math.E, -(eb - ea) / T)) {
                vec = vecb;
            }
            T *= cool;
        }
        System.out.println(scheduleCost(vec));
        return vec;
    }

    public int[] geneticoptimize(int popSize, int step, double mutprob, double elite, int maxiter) {
        long seed = System.nanoTime();
        Random random = new Random(seed);
        //构造初始种群
        ArrayList<int[]> pop = new ArrayList<int[]>(popSize);
        for (int i = 0; i < popSize; i++) {
            pop.add(randomResult());
        }

        //每一代胜出者数目
        int topelite = (int) (elite * popSize);
        ArrayList<Score> scores = new ArrayList<Score>();
        for (int j = 0; j < maxiter; j++) {
            for (int x = 0; x < popSize; x++) {
                Score s = new Score();
                s.list = pop.get(x);
                s.price = scheduleCost(pop.get(x));
                scores.add(s);
            }
            CompareScore cs = new CompareScore();
            Collections.sort(scores, cs);
            ArrayList<int[]> ranked = new ArrayList<int[]>();

            for (int m = 0; m < popSize; m++) {
                pop.remove(0);
                ranked.add(scores.get(m).list);
            }
            for (int n = 0; n < topelite; n++) {
                pop.add(ranked.get(n));
            }

            while (pop.size() < popSize) {
                if (random.nextDouble() < mutprob) {  //变异
                    int c = random.nextInt(topelite);
                    pop.add(mutate(ranked.get(c), step));
                } else {
                    int c1 = random.nextInt(topelite);
                    int c2 = random.nextInt(topelite);
                    pop.add(crossOver(ranked.get(c1), ranked.get(c2)));
                }
            }
            System.out.println(scores.get(0).price);
        }

        return scores.get(0).list;
    }

    /**
     * 变异
     * 
     * @param vec
     * @param step
     * @return
     */
    public int[] mutate(int[] vec, int step) {
        int[] mutateR = new int[MEMBER_NUM * 2];
        long seed = System.nanoTime();
        Random random = new Random(seed);
        int index = random.nextInt(MEMBER_NUM * 2 - 1);

        if (random.nextDouble() < 0.5 && vec[index] > 0) {
            for (int i = 0; i < MEMBER_NUM * 2; i++) {
                if (i == index && (vec[i] - step) > 0) {
                    mutateR[i] = vec[i] - step;
                } else {
                    mutateR[i] = vec[i];
                }
            }
        } else {
            for (int i = 0; i < MEMBER_NUM * 2; i++) {
                if (i == index && (vec[i] + step) < 9) {
                    mutateR[i] = vec[i] + step;
                } else {
                    mutateR[i] = vec[i];
                }
            }
        }

        return mutateR;
    }

    /**
     * 交叉
     * 
     * @param r1
     * @param r2
     * @return
     */
    public int[] crossOver(int[] r1, int[] r2) {
        int[] crossOverR = new int[MEMBER_NUM * 2];
        long seed = System.nanoTime();
        Random random = new Random(seed);
        int index = random.nextInt(MEMBER_NUM * 2 - 2);

        for (int i = 0; i < MEMBER_NUM * 2; i++) {
            if (i < index) {
                crossOverR[i] = r1[i];
            } else {
                crossOverR[i] = r2[i];
            }
        }

        return crossOverR;
    }

    /**
     * 产生一个长度为 MEMBER_NUM*2 的随机数组，数组中每个数字的值范围：(0, 9)
     *
     * @return r[<code>MEMBER_NUM</code> * 2]
     */
    public int[] randomResult() {
        long seed = System.nanoTime();
        Random random = new Random(seed);
        int[] r = new int[MEMBER_NUM * 2];
        for (int j = 0; j < MEMBER_NUM * 2; j++) {
            r[j] = random.nextInt(9);
        }
        return r;
    }

    public static void main(String[] args) {
        //int[] s = {1, 4, 3, 2, 7, 3, 6, 3, 2, 4, 5, 3};
        Optimization o = new Optimization();
        //System.out.println(o.getMinutes(o.flights.getTimeByValue("1:21")));
        o.initPeople();
        //int[] best = o.randomOptimize(100);
        //int[] best = o.hillclimb();
        // int[] best = o.annealingoptimize(10000.0, 0.95, 2);
        int[] best = o.geneticoptimize(50, 2, 0.2, 0.2, 100);
        o.printSchedule(best);

    }
}

 

/**
 *
 * FILENAME: Flights.java
 * AUTHOR:   vivizhyy[at]gmail.com
 * STUID:    whu
 * DATE:     2010-4-12
 * USAGE :
 */
package ch5.optimization;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;
import org.joda.time.LocalTime;

public class Flights {

    private String origin;
    private String dest;
    private LocalTime depart;
    private LocalTime arraive;
    private float price;
    public static String SCHEDULE = "schedule.txt";
    public Logger log = Logger.getLogger(Flights.class.getName());

    public Flights() {
    }

    public LocalTime getArraive() {
        return arraive;
    }

    public LocalTime getDepart() {
        return depart;
    }

    public String getDest() {
        return dest;
    }

    public Logger getLog() {
        return log;
    }

    public String getOrigin() {
        return origin;
    }

    public float getPrice() {
        return price;
    }


    public void setArraive(LocalTime arraive) {
        this.arraive = arraive;
    }

    public void setDepart(LocalTime depart) {
        this.depart = depart;
    }

    public void setDest(String dest) {
        this.dest = dest;
    }

    public void setLog(Logger log) {
        this.log = log;
    }

    public void setOrigin(String origin) {
        this.origin = origin;
    }

    public void setPrice(float price) {
        this.price = price;
    }

    /**
     * 
     * @return
     */
    public static Flights[] getFlights() {
        Flights flights[] = new Flights[120];
        for(int i = 0; i < 120; i++)
            flights[i] = new Flights();
        PropertyConfigurator.configure("D:/Documents/NetBeansProjects/CollectiveProgramming/src/log4j.properties");
        BufferedReader reader = null;
        String line;
        try {
            reader = new BufferedReader(new FileReader(SCHEDULE));
            int count = 0;
            while ((line = reader.readLine()) != null && count < 120) {
                //init flights
                String result[] = line.split(",");
                if (result.length == 5) {
                    flights[count].origin = result[0];
                    flights[count].dest = result[1];
                    flights[count].depart = getTimeByValue(result[2]);
                    flights[count].arraive = getTimeByValue(result[3]);
                    flights[count].price = new Integer(result[4]);

                    count++;
                } else {
                    System.err.println("schedule format wrong.");
                }
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }
        }
        return flights;
    }

    /**
     *
     * @param time
     * @return
     */
    public static LocalTime getTimeByValue(String time) {
        
        int mark = time.indexOf(":");
        int hour = new Integer(time.substring(0, mark));
        int minute = new Integer(time.substring(mark + 1, time.length()));
        
        LocalTime timeResult = new LocalTime(hour, minute);
        return timeResult;
    }

    /**
     * 
     * @param strOrigin
     * @param strDest
     * @return
     */
    public Flights[] getFlightByOriginAndDest(String strOrigin, String strDest) {
        Flights[] resultSet = new Flights[15];
        Flights flights[] = getFlights();
        int count = 0;
        for (Flights f : flights) {
            if(count > 14)
            {
                log.error("flight time lager than define.");
                break;
            }
            if (f.origin.equals(strOrigin) && f.dest.equals(strDest)) {
                    resultSet[count++] = f;
            }
        }

        return resultSet;
    }

    public String toString() {
        return this.origin + "\t"
                + this.dest + "\t"
                + this.depart + "-" + this.arraive + "\t"
                + "$" + this.price;
    }
}

 

 

/**
*
* FILENAME: Score.java
* AUTHOR:   [email protected]
* STUID:    whu200732580127
* DATE:     2010-4-13
* USAGE :   
*/
package ch5.optimization;

import java.util.Comparator;


public class Score {
    public int[] list = new int[12];
    public double price;
}

class CompareScore implements Comparator{

    public int compare(Object o1, Object o2) {
        Score s1 = (Score)o1;
        Score s2 = (Score)o2;
        int flag = 0;
        if(s1.price > s2.price)
            flag = 1;

        return flag;
    }

}