43 lines
1.3 KiB
Java
43 lines
1.3 KiB
Java
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package recursive;
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import java.util.*;
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public class TreeStructure {
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public static void main(String[] args) {
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List<TreeNode> treeNodes = new ArrayList<>();
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Set<Integer> leafSet = new HashSet<>();
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treeNodes.add(new TreeNode(1,0,"root"));
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treeNodes.add(new TreeNode(2,1,"a1"));
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treeNodes.add(new TreeNode(3,1,"a2"));
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treeNodes.add(new TreeNode(4,2,"b1"));
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treeNodes.add(new TreeNode(5,4,"c1"));
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Map<Integer, TreeNode> treeMap = new HashMap<>();
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for (TreeNode treeNode : treeNodes) {
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leafSet.add(treeNode.getId());
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}
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for (TreeNode treeNode : treeNodes) {
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treeMap.put(treeNode.getId(), treeNode);
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leafSet.remove(treeNode.getParentId());
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}
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for (Integer id: leafSet) {
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int parentId = treeMap.get(id).getParentId();
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int nodeId = id;
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while (parentId != 0) {
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treeMap.get(parentId).addChild(treeMap.get(nodeId));
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nodeId = parentId;
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parentId = treeMap.get(nodeId).getParentId();
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}
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}
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TreeNode finalNode = treeMap.values().stream()
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.filter(treeNode -> treeNode.getParentId() == 0).toList().getFirst();
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System.out.println(finalNode);
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}
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}
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