me.youm.frame.webmvc.tree.ForestNodeMerger Maven / Gradle / Ivy
package me.youm.frame.webmvc.tree;
import java.util.List;
/**
* 节点归并类
* @author youta
* @link https://blog.csdn.net/u014424628/article/details/51765394?utm_source=blogxgwz2
*/
public class ForestNodeMerger {
/**
* 将节点数组归并为一个森林（多棵树）（填充节点的children域）
* 时间复杂度为O(n^2)
*
* @param items 节点域
* @return 多棵树的根节点集合
*/
public static List merge(List items) {
ForestNodeManager forestNodeManager = new ForestNodeManager<>(items);
items.forEach(forestNode -> {
if (forestNode.getParentId() != 0) {
INode node = forestNodeManager.getTreeNodeAT(forestNode.getParentId());
if (node != null) {
node.getChildren().add(forestNode);
} else {
forestNodeManager.addParentId(forestNode.getId());
}
}
});
return forestNodeManager.getRoot();
}
}