我正在完成一项任务,我必须通过回溯来解决迷宫(使用堆栈!)并且代码的逻辑基本完成,但主要的问题是每当我在我的上调用pop()堆栈,它没有弹出。所以我现在手动添加(硬编码)迷宫里的部分应该pop()。我正在使用我自己的堆栈,它使用链接节点并运行JUnit和Main测试,它确实有效(现在在这里怀疑自己)。我也使用了Java堆栈,得到了相同的结果。
这是我的代码逻辑:正如你在方法mazeSolver中看到的那样,在底部,我有一些if语句检查我是否(执行的操作)是否在某一点,它将"回溯&# 34;,但我手动设置位置。最后一个else语句是我pop()的部分。非常感谢任何帮助。
public class MazeSolver {
private char[][] printMaze;
private char[][] solveMaze;
public MazeSolver() {
super();
}
private class Position {
private int x;
private int y;
Position(int y, int x) {
this.x = x;
this.y = y;
}
public int getX() {
return this.x;
}
public int getY() {
return this.y;
}
public void setX(int x) {
this.x = x;
}
public void setY(int y) {
this.y = y;
}
}
public boolean solve(boolean printUpdates) {
char space = ' ';
Stack<Position> stack = new Stack<Position>();
//Stack stack = new Stack();
Position cp = new Position(1, 0);
boolean done = true;
char c = 'C';
char x = 'X';
int i = 0;
while (done) {
// check right
if (printMaze[cp.getY()][cp.getX() + 1] == space && printMaze[cp.getY()][cp.getX() + 1] != x) {
cp.setX(cp.getX() + 1);
stack.push(cp);
printMaze[cp.getY()][cp.getX()] = 'C';
}
// check bottom
else if (printMaze[cp.getY() + 1][cp.getX()] == space && printMaze[cp.getY() + 1][cp.getX()] != x
&& printMaze[cp.getY() + 1][cp.getX()] != x) {
cp.setY(cp.getY() + 1);
stack.push(cp);
printMaze[cp.getY()][cp.getX()] = 'C';
}
// check top
else if (printMaze[cp.getY() - 1][cp.getX()] == space && printMaze[cp.getY() - 1][cp.getX()] != x) {
cp.setY(cp.getY() - 1);
stack.push(cp);
printMaze[cp.getY()][cp.getX()] = 'C';
}
// check left
else if (printMaze[cp.getY()][cp.getX() - 1] == space && printMaze[cp.getY()][cp.getX() - 1] != x) {
cp.setX(cp.getX() - 1);
stack.push(cp);
printMaze[cp.getY()][cp.getX()] = 'C';
}
//else {
/*
if (i == 6) {
printMaze[cp.getY()][cp.getX()] = 'X';
cp.setY(1);
cp.setX(5);
} else if (i == 27) {
printMaze[cp.getY()][cp.getX()] = 'X';
cp.setY(1);
cp.setX(20);
}
else if (i == 37) {
printMaze[cp.getY()][cp.getX()] = 'X';
cp.setY(2);
cp.setX(18);
}
else if (i == 68) {
printMaze[cp.getY()][cp.getX()] = 'X';
cp.setY(13);
cp.setX(22);
} else if (i == 69) {
printMaze[cp.getY()][cp.getX()] = 'X';
cp.setY(14);
cp.setX(22);
}
else if (i == 70) {
printMaze[cp.getY()][cp.getX()] = 'X';
cp.setY(15);
cp.setX(22);
} else if (i == 71) {
printMaze[cp.getY()][cp.getX()] = 'X';
cp.setY(16);
cp.setX(22);
} else if (i == 72) {
printMaze[cp.getY()][cp.getX()] = 'X';
cp.setY(17);
cp.setX(22);
} else if (i == 103) {
printMaze[cp.getY()][cp.getX()] = 'X';
cp.setY(21);
cp.setX(31);
} */else {
printMaze[cp.getY()][cp.getX()] = 'X';
stack.pop();
cp.setY(((Position) stack.top()).getY());
cp.setX(((Position) stack.top()).getX());
}
//}
i++;
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
// System.out.println(stack.top().getX() + ", " + stack.top().getY());
System.out.println(cp.getY() + ", " + cp.getX() + " i = " + i);
printMaze();
}
System.out.println("success");
return false;
}
public void printMaze() {
for (int i = 0; i < printMaze.length; i++) {
for (int j = 0; j < printMaze[i].length; j++) {
System.out.print(printMaze[i][j]);
}
System.out.println("");
}
}
public boolean loadMaze(String filename) {
BufferedReader br = null;
FileReader fr = null;
ArrayList<String> lines = new ArrayList<String>();
try {
fr = new FileReader(filename);
br = new BufferedReader(fr);
String line;
br = new BufferedReader(new FileReader(filename));
while ((line = br.readLine()) != null) {
lines.add(line);
}
printMaze = new char[lines.size()][];
solveMaze = new char[lines.size()][];
for (int i = 0; i < lines.size(); i++) {
printMaze[i] = new char[lines.get(i).length()];
solveMaze[i] = new char[lines.get(i).length()];
for (int j = 0; j < lines.get(i).length(); j++) {
solveMaze[i][j] = lines.get(i).charAt(j);
printMaze[i][j] = lines.get(i).charAt(j);
if (solveMaze[i][j] == 'S') {
// hint you need to do this but you do not have the
// instance variable yet
// start = new Position(i, j);
}
}
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (br != null)
br.close();
if (fr != null)
fr.close();
} catch (IOException ex) {
return false;
}
}
return true;
}
如果感兴趣,这是我的堆栈实现。
public class Stack<Item> implements StackInterface<Item> {
private int size;
private class Link {
private Item data;
public Link next;
public Link(Item data, Link next) {
this.data = data;
this.next = next;
}
public Item getData() {
return data;
}
}
private Link topStackLink = null;
public Stack() {
this.size = 0;
}
@Override
public void push(Item item) {
if (topStackLink == null) {
topStackLink = new Link(item, null);
} else {
topStackLink = new Link(item, topStackLink);
}
this.size++;
}
@Override
public void pop() {
// TODO Auto-generated method stub
if (topStackLink != null) {
topStackLink = topStackLink.next;
this.size--;
} else {
throw new java.util.EmptyStackException();
}
}
@Override
public Item top() {
if (topStackLink != null) {
return topStackLink.data;
} else {
throw new java.util.EmptyStackException();
}
}
@Override
public Item topAndPop() {
// TODO Auto-generated method stub
if (topStackLink != null) {
Item item = topStackLink.data;
pop();
return item;
} else {
throw new java.util.EmptyStackException();
}
}
@Override
public boolean isEmpty() {
if (topStackLink == null) {
return true;
} else {
return false;
}
}
@Override
public void makeEmpty() {
// TODO Auto-generated method stub
topStackLink = null;
this.size = 0;
}
@Override
public int size() {
return this.size;
}