* 有一根27厘米的细木杆，在第3厘米、7厘米、11厘米、18厘米、23厘米这五个位置上各有一只蚂蚁。
* 木杆很细，不能同时通过两只蚂蚁。开始时，蚂蚁的头朝左还是朝右是任意的，它们只会朝前走或调头，但不会后退。
* 当任意两只蚂蚁碰头时，两只蚂蚁会同时调头朝反方向走。假设蚂蚁们每秒钟可以走一厘米的距离。编写程序，求所有蚂蚁都离开木杆的最小时间和最大时间。
*
* 要求：用类模拟出蚂蚁的行为特性，进而模拟出五只蚂蚁在木杆上的运行过程来编程求解。不能通过数学的方式直接用公式计算。
public class AntMove {
public static void main(String[] args) {
int a[]={3,7,11,18,23};
Ant ants[]=new Ant[a.length];
Ant.setANT_NUM(a.length);
int numOfDirectionStates=1;
for(int i=0;i<a.length;i++){
numOfDirectionStates*=2;
}
for(int i=0;i<a.length;i++){
ants[i]=new Ant(numOfDirectionStates);
}
boolean directionStates[][]=new boolean[numOfDirectionStates][a.length];
for(int i=0;i<numOfDirectionStates;i++){
for(int j=0;j<a.length;j++){
directionStates[i][j]=( (i&(1<<j) )==0 );
}
}
for(int i=0;i<numOfDirectionStates;i++){
for(int j=0;j<a.length;j++){
ants[j].setDown(false);
ants[j].setLeft(directionStates[i][j]);
ants[j].setPos(a[j]);
}
Ant.setNumOfDown(0);
Ant.setTime(0);
while(true){
print(ants);
Ant.timeMove();
for(int j=0;j<a.length;j++){
ants[j].move(1);
}
for(int j=0;j<a.length-1;j++){
if(!ants[j].isLeft() && ants[j+1].isLeft() &&
!ants[j].isDown() && !ants[j+1].isDown()){
if(ants[j].getPos()==ants[j+1].getPos()){
System.out.println("发生碰头，掉头走");
ants[j].turnRound();
ants[j+1].turnRound();
}
if(ants[j].getPos()>ants[j+1].getPos()){
System.out.println("发生撞头，这步无效，回退一步，掉头走");
ants[j].move(-1);
ants[j+1].move(-1);
ants[j].turnRound();
ants[j+1].turnRound();
}
}
}
if(Ant.getNumOfDown()==a.length){
break;
}
}
}
int times[]=Ant.getTimes();
System.out.println("最终结果：");
System.out.println("minTime="+Ant.getMinTime());
System.out.println("最短时间掉下杆子的各个蚂蚁运动情况如下：");
int count=0;
for(int i=0;i<times.length;i++){
if( times[i]==Ant.getMinTime() ){
System.out.println("第"+(++count)+"种");
for(int j=0;j<ants.length;j++){
if(directionStates[i][j]){
System.out.println("第"+(j+1)+"个球往左");
}else{
System.out.println("第"+(j+1)+"个球往右");
}
}
}
}
System.out.println();
System.out.println("maxTime="+Ant.getMaxTime());
System.out.println("最长时间掉下杆子的各个蚂蚁运动情况如下：");
count=0;
for(int i=0;i<times.length;i++){
if( times[i]==Ant.getMaxTime() ){
System.out.println("第"+(++count)+"种");
for(int j=0;j<ants.length;j++){
if(directionStates[i][j]){
System.out.println("第"+(j+1)+"个球往左");
}else{
System.out.println("第"+(j+1)+"个球往右");
}
}
}
}
}
private static void print(Ant ants[]) {
boolean isFirst=true;
for(int i=0;i<ants.length;i++){
if(isFirst){
isFirst=false;
System.out.print(ants[i].getPos());
}else{
System.out.print(", "+ants[i].getPos());
}
}
System.out.println();
}
}
class Ant{
public final static int LEFT_END=0;
public final static int RIGHT_END=0;
private static int numOfDown;
private static int time;
private static int ANT_NUM;
private static int minTime=Integer.MAX_VALUE;
private static int maxTime=-1;
private static int times[];
private static int count;
private boolean left;
private int pos;
private boolean down;
public Ant(int a) {
times=new int[a];
}
public void move(int n){
if(!down){
if(left){
pos-=n;
}else{
pos+=n;
}
if(pos<=0||pos>=27){
down=true;
numOfDown++;
if(numOfDown==ANT_NUM){
System.out.println("蚂蚁全部掉下去了");
if(time<minTime){
minTime=time;
}
if(time>maxTime){
maxTime=time;
}
times[count]=time;
count++;
System.out.println("用去时间为："+time);
System.out.println("此时最小时间为:"+minTime);
System.out.println("此时最大时间为:"+maxTime);
}
}
}
}
public static int[] getTimes() {
return times;
}
public static void setTimes(int[] times) {
Ant.times = times;
}
public static int getNumOfDown() {
return numOfDown;
}
public static void setNumOfDown(int numOfDown) {
Ant.numOfDown = numOfDown;
}
public static int getTime() {
return time;
}
public static void setTime(int time) {
Ant.time = time;
}
public static void timeMove() {
Ant.time++;
}
public static int getANT_NUM() {
return ANT_NUM;
}
public static void setANT_NUM(int aNT_NUM) {
ANT_NUM = aNT_NUM;
}
public static int getMinTime() {
return minTime;
}
public static void setMinTime(int minTime) {
Ant.minTime = minTime;
}
public static int getMaxTime() {
return maxTime;
}
public static void setMaxTime(int maxTime) {
Ant.maxTime = maxTime;
}
public boolean isLeft() {
return left;
}
public void setLeft(boolean left) {
this.left = left;
}
public int getPos() {
return pos;
}
public void setPos(int location) {
this.pos = location;
}
public boolean isDown() {
return down;
}
public void setDown(boolean down) {
this.down = down;
}
public void turnRound(){
left=!left;
}
}
