日期:2014-05-20 浏览次数:20908 次
public class MovingProcessor {
//所谓四面八方,把方向控制好就行了
//以2维坐标为参考,前为上(y坐标增加),右为右(x坐标增加),后为下(y坐标减少),左为左(x坐标减少)
private static final int[][] MOVING_DIR = {{0,1}, {1,0}, {0,-1}, {-1,0}};
protected int dir = 0; //用于控制方向
protected double x = 0; //用于控制x坐标
protected double y = 0; //用于控制y坐标
private boolean isolating = true; //是否是独立的命令(用于扩展,此题可忽略),因为是每次独立计算距离(即后面的距离不累加前面的距离),所以本题设为独立命令
//private boolean realTime = false;//是否是实时处理(用于扩展,此题忽略)
public MovingProcessor() {}
public MovingProcessor(boolean isolating) {
this.isolating = isolating;
}
public void reset() { //处理器重置
dir = 0;
x = 0;
y = 0;
}
public double execute(String cmd) throws Exception { //执行指令,支持小数距离(题目给的是整数距离,这里扩展支持小数距离)
if (isolating) reset();
int dec = 0; //小数标志
double num = 0, times = 0;
for (char c : cmd.toCharArray()) { //按字符遍历指令
if (c == 'L') { //遇到左转L指令
if (num > 0) {//判断是否L指令前是否存在移动距离,如果存在,则先移动
move(num); //移动距离
num = 0;
dec = 0;
}
changeDir(c); //改变方向
} else if (c == 'R') { //遇到R右转指令
if (num > 0) {
move(num);
num = 0;
dec = 0;
}
changeDir(c);
} else if (c>='0' && c<='9') { //遇到数字累加数字
if (dec == 0) { //无小数的时候
num = num*10 + (c-'0');
} else { //有小数的时候
num += (c-'0')/times;
times *= 10;
}
} else if (c == '.') { //遇到小数点
if (dec > 0) { //非法小数点则抛出异常
throw new Exception(String.format("Error Command[%s].", cmd));
}
dec = 1;
times = 10;
} else { //非法字符则抛出异常
throw new Exception(String.format("Error Command[%s].", cmd));
}
}
if (num > 0) { //如果有移动距离就移动
move(num);
}
return Math.sqrt(x*x + y*y); //返回移动的距离
}
protected void changeDir(char dir) { //改变方向
this.dir += (dir=='L' ? -1 : (dir=='R' ? 1 : 0));
}
protected void move(double value) { //移动距离
dir %= 4;
dir += (dir < 0) ? 4 : 0;
x += value * MOVING_DIR[dir][0];
y += value * MOVING_DIR[dir][1];
}
public static void main(String[] args) {
String[] cmds = getCmds();
MovingProcessor mp = new MovingProcessor();
System.out.println("Execute Result:");
for (String cmd : cmds) {
try {
System.out.printf("%.2f\n", mp.execute(cmd));
} catch (Throwable e) {
e.printStackTrace();
//break; //skip, ignore, cancel, so on...
}
}
}
public static String[] getCmds() {
String[] cmds;
int count = 0;
Scanner sc = new Scanner(System.in);
try {
System.out.println("User Input:");
count = Integer.valueOf(sc.nextLine()).intValue();
} catch (Throwable e) {
e.printStackTrace();
System.exit(-1);
}
cmds = new String[count];
for (count=0; count<cmds.length; count++) {
cmds[count] = sc.nextLine();
}
return cmds;
}
}