/*
* Created on 13-1-25
*
* 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.
*
* Copyright @2013 the original author or authors.
*/
package ch08algorithm;
import java.util.*;
/**
* 25匹马中找出跑的最快的3匹马
* <p/>
* 说明：
* 25匹马比赛花费时间各不相同，
* 没有秒表，只能观察排名，而且每次只能5匹马在跑道上比赛
*
* @author XiongNeng
* @version 1.0
* @since 13-1-25
*/
public class TwentyFiveHorses {
public static void main(String[] args) {
new TwentyFiveHorses().imitateRace();
}
/**
* 模拟赛马
*/
public void imitateRace() {
List<List<Horse>> all = new ArrayList<List<Horse>>();
List<Horse> candidateList = new ArrayList<Horse>();
List<Integer> randomInteger = new ArrayList<Integer>();
for (int i = 0; i < 25; i++) {
randomInteger.add(i);
}
Collections.shuffle(randomInteger);
for (int i = 0; i < 25; i++) {
Horse horse = new Horse(i + 1, (i / 5) + 1);
horse.setExpendTime(randomInteger.get(i) + 1);
if (i % 5 == 0) {
List<Horse> list = new ArrayList<Horse>();
all.add(list);
}
all.get(all.size() - 1).add(horse);
}
System.out.println("---------这次比赛的马儿的数据：这些数据我看不到-------");
for (List<Horse> list : all) {
candidateList.addAll(list);
for (Horse horse : list) {
System.out.println(horse);
}
}
System.out.println("----------打印马儿数据完成了-----------");
System.out.println();
int raceCount = 0;
int groupId = 0;
List<Horse> headList = new ArrayList<Horse>();
System.out.println("首先5组分别进行比赛");
for (List<Horse> eachGroup : all) {
raceCount++;
groupId++;
System.out.println("第" + raceCount + "轮比赛，组号为" + groupId + "的比赛开始");
Collections.sort(eachGroup, new Comparator<Horse>() {
@Override
public int compare(Horse o1, Horse o2) {
return o1.getExpendTime() < o2.getExpendTime() ? 1 : 0;
}
});
headList.add(eachGroup.get(4));
for (int i = 0; i < eachGroup.size() - 1; i++) {
eachGroup.get(i).setNext(eachGroup.get(i + 1));
}
System.out.println("每小组比赛结果，排名从后到前的马儿编号为：");
for (Horse each : eachGroup) {
System.out.print(each.getId() + " ");
}
System.out.println();
System.out.println("--------------------分割线------------------------");
System.out.println();
}
System.out.println("第6轮比赛，接下来把上面5组比赛的第一名拿出来比赛");
String ids = "";
for (Horse h : headList) {
ids += h.getId() + " ";
}
System.out.println("这组5匹马的编号为： " + ids);
Collections.sort(headList, new Comparator<Horse>() {
@Override
public int compare(Horse o1, Horse o2) {
return o1.getExpendTime() < o2.getExpendTime() ? 1 : 0;
}
});
System.out.println("第6轮比赛结果，排名从后到前的马儿编号为：");
for (int i = 0; i < headList.size() - 1; i++) {
headList.get(i).setNext(headList.get(i + 1));
}
for (Horse each : headList) {
System.out.print(each.getId() + " ");
}
System.out.println();
Horse champion = headList.get(headList.size() - 1);
System.out.println("第一名率先出来了，id编号为" + champion.getId());
candidateList.remove(champion);
System.out.println("接下来，将所有与第一名的路径大于2的马儿淘汰掉（这里是核心算法）");
Iterator<Horse> iterator = candidateList.iterator();
while (iterator.hasNext()) {
Horse horse = iterator.next();
int i = 0;
while (horse.next != null) {
i++;
if (i > 2) {
iterator.remove();
break;
}
horse = horse.next;
}
}
System.out.println("第6轮过后，剩下有资格争夺排名的马儿:");
for (Horse horse : candidateList) {
System.out.println(horse);
}
assert candidateList.size() == 5;
System.out.println("从以上结果看出，刚好还剩5匹马儿可以争夺最后的第2，第3名");
System.out.println();
System.out.println("--------------------分割线------------------------");
System.out.println("第7轮比赛开始：");
Collections.sort(candidateList, new Comparator<Horse>() {
@Override
public int compare(Horse o1, Horse o2) {
return o1.getExpendTime() < o2.getExpendTime() ? 1 : 0;
}
});
System.out.println("最后一场比赛比赛结果，排名从后到前的马儿编号为：");
for (Horse aCandidateList : candidateList) {
System.out.print(aCandidateList.getId() + " ");
}
System.out.println();
System.out.println("然后第2名和第3名也出来了");
System.out.println();
System.out.println("-------------------最后比赛结果：---------------");
System.out.println("第1名id为" + champion.getId());
System.out.println("第2名Id为：" + candidateList.get(candidateList.size() - 1).getId());
System.out.println("第3名Id为：" + candidateList.get(candidateList.size() - 2).getId());
System.out.println();
System.out.println("------------------------结束模拟---------------------");
}
private class Horse {
/**
* 编号
*/
private int id;
/**
* 组号
*/
private int groupId;
/**
* 跑完花费的时间
*/
private int expendTime;
/**
* 排名的前驱结点
*/
private Horse next;
private Horse(int id, int groupId) {
this.id = id;
this.groupId = groupId;
}
/**
* **********getter and setter***********
*/
public int getExpendTime() {
return expendTime;
}
public void setExpendTime(int expendTime) {
this.expendTime = expendTime;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getGroupId() {
return groupId;
}
public void setGroupId(int groupId) {
this.groupId = groupId;
}
public Horse getNext() {
return next;
}
public void setNext(Horse next) {
this.next = next;
}
public String toString() {
return "id:" + id + " | groupID:" + groupId + " | expendTime:" + expendTime;
}
}
}