table of Contents
topic:
Enter from the leftmost 0 subscript, and the rightmost 9 subscript. The number in the array is the change value of the subscript position. Find the jumping path from the beginning to the end. Note that the marker can be moved to the left or right along the line, but it cannot be moved beyond either end.
Ideas
Use the stack to save the nodes that have been walked, if it fails, go back and jump to find a new path from the direction where the last node did not jump
Test Data
-
4 8 5 2 3 5 1 6 4 0
-
4 8 5 2 3 5 1 3 4 0
-
4 3 5 2 3 5 1 3 4 0
Code:
Puzzle.java
import java.util.Scanner;
import java.util.Stack;
public class Puzzle {
private PuzzleNode[] puzzleNodes;
private Stack<PuzzleNode> stack;
Puzzle() {
puzzleNodes=new PuzzleNode[10];
stack=new Stack<PuzzleNode>();
}
private void initValue() {
System.out.println("请输入长为10的puzzle序列：");
Scanner sc=new Scanner(System.in);
for(int i=0;i<puzzleNodes.length;i++) {
puzzleNodes[i]=new PuzzleNode(sc.nextInt(),i);
}
}
//初始左右状态(越界 或重复)
private void innitState() {
for(int i=0;i<puzzleNodes.length;i++) {
if(puzzleNodes[i].getIndex()+puzzleNodes[i].getValue() < puzzleNodes.length) {
puzzleNodes[i].setRight(true);
}
if(puzzleNodes[i].getIndex()-puzzleNodes[i].getValue() >=0) {
puzzleNodes[i].setLeft(true);
}
}
}
//从首位置走到末位置
//默认先找右边；不通则找另一边，还不行，则回退
public void goPuzzle(){
initValue();
innitState();
stack.push(puzzleNodes[0]);
while(!stack.isEmpty()) {
PuzzleNode top=stack.peek();
//已走到
if(top.getIndex()==puzzleNodes.length-1) {
break;
}
//避免成环和重复
if(top.getRight()==true ) {
stack.push( puzzleNodes[top.getIndex()+top.getValue()] );
//将当前结点的走过方向（右）封掉，因为若不通，下次肯定不会走该方向了
top.setRight(false);
//下一结点的往回来方向（左）不一定会跳到当前结点
}else if(top.getLeft()==true) {
stack.push( puzzleNodes[top.getIndex()-top.getValue()] );
top.setLeft(false);
}else if(!top.getRight()&&!top.getLeft()) {
//左右都不通，不修改他的左右状态，直接压栈又出栈
stack.pop();
}
}
show();
}
private void show() {
// TODO Auto-generated method stub
// TODO Auto-generated method stub
if(stack.isEmpty()) {
System.out.println("没有迷宫路径");
return;//退出
}
//调整顺序
Stack<PuzzleNode> temp=new Stack<PuzzleNode>();
while(!stack.isEmpty()) {
temp.push(stack.peek());
stack.pop();
}
System.out.println("路径已找到，如下：");
while(!temp.isEmpty()) {
System.out.print(temp.peek().getValue()+" ");
temp.pop();
}
}
}
PuzzleNode.java
public class PuzzleNode {
private int value;
private boolean left;
private boolean right;
private int index;//在数组中的下标
public PuzzleNode(int value,int index) {
// TODO Auto-generated constructor stub
this.setValue(value);
this.setIndex(index);
}
public int getIndex() {
return index;
}
public void setIndex(int index) {
this.index = index;
}
public int getValue() {
return value;
}
public void setValue(int value) {
this.value = value;
}
public boolean getRight() {
return right;
}
public void setRight(boolean flag) {
this.right = flag;
}
public boolean getLeft() {
return left;
}
public void setLeft(boolean flag) {
this.left = flag;
}
}
PuzzleTest.java
public class PuzzleTest {
public static void main(String[] args) {
// TODO Auto-generated method stub
Puzzle puzzle=new Puzzle();
puzzle.goPuzzle();
}
}