有 Java 编程相关的问题?

你可以在下面搜索框中键入要查询的问题!

使用DepthFirstSearch算法的java骑士之旅

我正在尝试使用DFS制作程序knight tour,但我无法解决此程序。。因为我总是有这样的信息错误

java线程“AWT-EventQueue-0”中出现异常。lang.ArrayIndexOutofBounds异常:-1 在爪哇。util。ArrayList。elementData(ArrayList.java:371) 在爪哇。util。ArrayList。get(ArrayList.java:384) 在骑士之旅。processKnightTour(KnightTour.java:82)

我希望有人能帮助我

public void processKnightTour(int indexX, int indexY){
    System.out.println(indexX);
    System.out.println(indexY);
    int[] x={2,2,-2,-2,1,1,-1,-1};
    int[] y={1,-1,1,-1,2,-2,2,-2};
    int countPath=0;
    workList = new ArrayList();
    node[indexX][indexY] = 1;
    workList.add(new Coordinate(indexX, indexY));
    current =(Coordinate) workList.get(workList.size()-1);
    boolean statusChild;
    while(node[current.row][current.column] != 64){
        statusChild = false;
        for(int loop=0; loop<8; loop++){
            if(current.row+x[loop]>=0 && current.row+x[loop]<=7 && current.column+y[loop]>=0 && current.column+y[loop]<=7){
                if(node[(current.row+x[loop])][(current.column+y[loop])]==0){
                    workList.add(new Coordinate(current.row+x[loop], current.column+y[loop], current));
                    statusChild = true;
                }                    
            }
        }
        if(statusChild == true){
            workList.remove(workList.indexOf(current));
        }else{
            if(workList.size()-2 >= 0){
                after = (Coordinate) workList.get(workList.size()-2);
                if(current.nodeParent.equals(after.nodeParent)){

                }else{
                    node[current.nodeParent.row][current.nodeParent.column] = 0;
                }
            }
            node[current.row][current.column] = 0;                
            workList.remove(workList.size()-1);
        }
        current = (Coordinate) workList.get(workList.size()-1);
        node[current.row][current.column] = (node[current.getParent().row][current.getParent().column])+1;
        countPath++;
        //System.out.println(countPath+", "+workList.size()+", "+node[current.column][current.row]);
    }

}

共 (1) 个答案

  1. # 1 楼答案

            workList.remove(workList.size()-1);
        }
        current = (Coordinate) workList.get(workList.size()-1);
    

    在这段代码的末尾,您将:

    • 首先在不知道列表中是否有元素的情况下删除元素
    • 其次,您尝试从一个列表中get(worklist.size()-1),该列表可以(并且将)大小为0

    你的while循环中有一些不太正确的地方。我没有清楚地看到意图,但您应该以某种方式确保workList使用正确