如何为节点迭代设置 do...while

Question

我的目标是迭代我创建的节点搜索逻辑。为此，我实施了一个 do...while 条件。在 do{} 中，我从初始状态和初始节点说 "choose the action that satisfy the precondition with the lower cost"。找到后，将初始状态和节点设置为新的。在 while() 中，我表达了条件 "until the state is equal to the goal state" go ahead.

问题是，当我运行这个时，只打印第一次迭代的结果，但似乎仍在继续计算，没有停止。

这是代码

private static Node nodeStatus;

static  Action loadPlaneP1 = new Action("loadPlaneP1",pkg1Location[1], pkg2Location[0], truckLocation[0], planeLocation[0], cityLocation[0], 30);
static  Action loadPlaneP2 = new Action("loadPlaneP2", pkg1Location[0], pkg2Location[1], truckLocation[0], planeLocation[0], cityLocation[0], 40);
....//other actions



 State state = new State(0, pkg1Location[0], pkg2Location[0], truckLocation[0], planeLocation[0], cityLocation[0]);
 State newState = new State(0, pkg1Location[0], pkg2Location[0], truckLocation[0], planeLocation[0], cityLocation[0]);
 static State goal = new State(0, pkg1Location[5], pkg2Location[4], truckLocation[3], planeLocation[2], cityLocation[1]);

 static Action[] acts = {loadPlaneP1, loadPlaneP2, fly, unloadPlaneP1, unloadPlaneP2, loadTruckP1, loadTruckP2, drive, unloadTruckP1, unloadTruckP2 };

Node startNode = new Node(state, 0);

int[] costs = {loadPlaneP1.getActionCost(), loadPlaneP2.getActionCost(), fly.getActionCost(), unloadPlaneP1.getActionCost(), unloadPlaneP2.getActionCost(), loadTruckP1.getActionCost(), loadTruckP2.getActionCost(), drive.getActionCost(), unloadTruckP1.getActionCost(),unloadTruckP2.getActionCost()};      



 do{

         if(nodeStatus != startNode) {
               nodeStatus = startNode;
            }
             else {
               nodeStatus = startNode;
                  }


         if(nodeStatus == startNode) {


         System.out.println("Old state parameters are " + "pkg1Location: " + state.getStateParameter1() + " pkg2Location: " + state.getStateParameter2() + " truckLocation: "+ state.getStateParameter3() + " planeLocation: " + state.getStateParameter4() + " cityLocation:"+ state.getStateParameter5());




            for(int i = 0; i < acts.length; i++) {


                if(acts[i].getActionCost() == getMinValue(costs)) {

                   System.out.println("PRE The first parameter is : " + acts[i].getActParameter1() + acts[i].name +" "+ acts[i].actionCost);



                      if(acts[i].loadPlaneP1Precondition() == true) {

                          System.out.println("POST The first parameter is : " + acts[i].getActParameter1());
                          System.out.println("Precondition satysfied" + " with action name: " + acts[i].name);

                      if(acts[i].getActParameter1() != state.getStateParameter1()) {

                          newState.setStateParameter1(acts[i].getActParameter1());
                         }

                      if(acts[i].getActParameter2() != state.getStateParameter2()) {
                         if(acts[i].getActParameter2() != State.pkg2Location[1]) {

                         newState.setStateParameter2(acts[i].getActParameter2());
                            } 
                         }

                      if(acts[i].getActParameter3() != state.getStateParameter3()) {

                         newState.setStateParameter3(acts[i].getActParameter3());
                         }

                      if(acts[i].getActParameter4() != state.getStateParameter4()) {

                         newState.setStateParameter4(acts[i].getActParameter4());
                         }

                      if(acts[i].getActParameter5() != state.getStateParameter5()) {

                         newState.setStateParameter5(acts[i].getActParameter5());
                         }

                         acts[i].setActCost(100);
            } 

               ................................//checking other preconditions



            Node child = new Node("Node "+ i, newState, startNode, acts[i].getActionCost(), acts[i].name);



            startNode = child;
            state = newState;




            System.out.println("Costs array: "+  Arrays.toString(costs));
            System.out.println("ActionID" +" " +  i);
            System.out.println("The action choosen is " + acts[i].name +" "+ acts[i].actionCost +" "+ acts[i].getActParameter1());
            System.out.println("State parameters updated are " + "pkg1Location: " + state.getStateParameter1() + " pkg2Location: " + state.getStateParameter2() + " truckLocation: "+ state.getStateParameter3() + " planeLocation: " + state.getStateParameter4() + " cityLocation:"+ state.getStateParameter5());
            System.out.println("The node created is : " + child.getNodeName());
                }


            }


        }



    }while(state == goal);

如何打印每次迭代的结果？

Answer 1

在循环结束时，您正在检查 while(state == goal)。
试试 while (state.equals(goal));.

您应该在比较对象实例时使用 equals 方法（除非它们是枚举，这似乎不是您的情况）。

对了，你说"until the state is equal to the goal state"继续。
这将被翻译成 while (!state.equals(goal));（不等于）。

更新：
此外，在循环的开头，您有以下代码：

if(nodeStatus != startNode) {
               nodeStatus = startNode;
            }
             else {
               nodeStatus = startNode;
                  }


         if(nodeStatus == startNode) {

首先，在这里您也是通过等号而不是等号方法来比较 2 个对象。
此外，在任何一种情况下，您都将 startNode 分配给 nodeStatus。之后的 if 条件将始终为真。

Answer 2

您应该尝试 Robert Kock 的解决方案。

您需要检查：

如果状态 class 是由您创建的，您应该覆盖 equals 方法（这样您就不会比较对象的地址）。
并遵循 Robert Kock 的解决方案 while (!state.equals(goal));

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