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我正在爲所有節點添加到數組列表names
的樹進行遞歸方法。此方法無法將葉節點(沒有子節點的節點)添加到陣列列表names
。以樹方法打印所有節點
它只將根和根的子節點添加到數組列表中。爲了解決其他遞歸問題,我需要知道什麼是錯誤的。
private ArrayList<TreeNode> names = new ArrayList<>();
public ArrayList<TreeNode> getAllNodes(){
//BASIS CASES:
names.add(this);
if(isLeaf()){
names.add(this);
return names;
}
//RECURSIVE CASES:
for(TreeNode child : children){
child.getAllNodes();
names.add(child);
}
return names;
}
其他代碼:
//prints the nodes out
ArrayList<TreeNode> theNodes = treeRoot.getAllNodes();
System.out.println("");
for (TreeNode n : theNodes) System.out.print(n.getLabel() + " ");
repaintCanvas(canvas);
//hard coded nodes
treeRoot = new TreeNode(TreeNode.Gender.MALE, "John", null);
itemsToDraw.add(treeRoot);
TreeNode Louis = new TreeNode(TreeNode.Gender.MALE, "Louis", treeRoot);
TreeNode Sue = new TreeNode(TreeNode.Gender.FEMALE, "Sue", treeRoot);
TreeNode Anne = new TreeNode(TreeNode.Gender.FEMALE, "Anne", Sue);
TreeNode Sam = new TreeNode(TreeNode.Gender.MALE, "Sam", Sue);
TreeNode Anne2 = new TreeNode(TreeNode.Gender.FEMALE, "Anne", Sam);
TreeNode Ed = new TreeNode(TreeNode.Gender.MALE, "Ed", Louis);
TreeNode Frank = new TreeNode(TreeNode.Gender.MALE, "Frank", Louis);
輸出:
約翰·路易斯·薩