一个领导者选举算法
根据Matrix67的"囚徒与灯泡"文章而写：
public class Wakeup {static class People {//记录第一次进入时确定的位置 0未确定,-1 左边 1右边.public int Position;//手上的球public int BallNum;//标识public int Id;//是否还在参与跷跷板游戏public boolean OnLine;public People(int Id) {this.Id = Id;Position = 0;BallNum = 2;OnLine = true;}}private static int PeopleCount=100;//参与者人数private static boolean BoxIsEmpty = true;// 盒子是否是空的private static boolean LeftIsWeight = false;//跷跷板左边低public static void main(String[] args) {People[] thePeoples = new People[100];for (int i = 0; i < PeopleCount; i++) {thePeoples[i] = new People(i);}boolean finished = false;int k = 0;int i = 0;int outNum = 0;while (!finished) {k++;i = (new Random().nextInt(PeopleCount)) % PeopleCount;People theP = thePeoples[i];if (theP.OnLine) {if (theP.Position == 0) {theP.Position = LeftIsWeight ? -1 : 1;LeftIsWeight = !LeftIsWeight;} else {if (theP.Position == -1) {if (LeftIsWeight) { // 左边本侧低,如果有球则取if (!BoxIsEmpty) {BoxIsEmpty = true;theP.BallNum++;}} else {// 本侧高,空就放球if (BoxIsEmpty) {if (theP.BallNum > 0) {theP.BallNum--;BoxIsEmpty = false;}}}} else {if (LeftIsWeight) {// 本侧高,空就放球if (BoxIsEmpty) {if (theP.BallNum > 0) {theP.BallNum--;BoxIsEmpty = false;}}} else {// 本侧低,非空就取球if (!BoxIsEmpty) {BoxIsEmpty = true;theP.BallNum++;}}}}//如果没有球,则退出,什么都不做if (theP.BallNum <= 0) {LeftIsWeight = !LeftIsWeight;theP.OnLine = false;outNum++;System.out.println("Out:" + theP.Id);}//如果收集到200个球或者199个球,另外一个球在盒子里,则表示获得胜利.if (theP.BallNum + (BoxIsEmpty ? 0 : 1) >= PeopleCount * 2) {System.out.println("胜利者:" + theP.Id + ",共执行:" + k);finished = true;}}}}}
PS：这个算法提供了一种很好的思路，但在实际选举策略中一般都不会用，因为条件不会如文章所假设的那种苛刻的场景。