拥有原始和“最终”/ 结果树。我想比较这些树木并“重现”这些步骤,这些步骤将被携带以获得相同的结果。将原始树合并到结果树中的步骤
现实生活中的例子:在数据库中有原始树。工作人员已准备好更改(在App中生成新的结果树),现在我们需要更新数据库。我们无法删除数据库并重新上传,因为可能有尚未生成的数据。
类/表定义:
class TreeNode
{
public string Text { get; set; }
public TreeNode Parent { get; set; }
/* some other properties */
}
实施例的树木:
Origin Result
|A |A
| -1 | -2
| -2 |C
|B | -3
| -5 |D
| --£ | -1
|C | --£
|F | -5
| -7 |E
|H | -6
|G
| -4
|H
我希望是有一个算法,通过该我将被允许处理时的对象是加入 ,删除或移动。
重要信息:有其他家长不应该删除和加入后面的对象,相反,他们应该只有下其他家长感动!删除会导致数据丢失。
实施例:
Mark B as removed
Mark F as removed
Add D
Add E
Add G
Move 1 under D
Move 5 under D
Mark 7 as removed
Add 3 under C
Add 6 under E
Add 4 under G
Move £ under 1
Removed 7
Removed F
Removed B
自己的解决方案
我创建样品与的Win-形式和的TreeView。我的算法仅适用于每个级别的基础(例如,将1从A移动到D),但不能跨越。元素是第一个被删除的市场,最后被删除。
代码:
//Recursive loop to find all nodes in Nth level
private IEnumerable<TreeNode> getNodesOnLevel(TreeNodeCollection aCollection, int aLevel)
{
var lResultTreeNodeCol = new List<TreeNode>();
if (aLevel == 1)
return aCollection.Cast<TreeNode>();
foreach(TreeNode nNode in aCollection)
{
lResultTreeNodeCol.AddRange(getNodesOnLevel(nNode.Nodes, aLevel - 1));
}
return lResultTreeNodeCol;
}
//Called once
public void UpdateTrees(TreeNodeCollection aCollectionA, TreeNodeCollection aCollectionB)
{
List<TreeNode> lRemoved = new List<TreeNode>();
for (int i = 1; UpdateWithLevel(aCollectionA, aCollectionB, i, ref lRemoved) > 0; i++)
{
}
var lRem = lRemoved.LastOrDefault();
do
{
W($"Removed {lRem.Text}");
lRemoved.Remove(lRem);
} while ((lRem = lRemoved.LastOrDefault()) != null);
}
//Called per level
private int UpdateWithLevel(TreeNodeCollection aCollectionA, TreeNodeCollection aCollectionB, int level, ref List<TreeNode> aRemoved)
{
int lNumOfUpdates = 0;
var colA = getNodesOnLevel(aCollectionA, level);
var colB = getNodesOnLevel(aCollectionB, level);
//Search Original collection, compare to Result collection
foreach (TreeNode nodeA in colA)
{
//Find nodeA in Result collection
var lNodeAinColB = colB.FirstOrDefault((a) => a.Text == nodeA.Text);
if(lNodeAinColB == null) //NodeA not found in result collection - delete
{
aRemoved.Add(nodeA);
W($"Mark {nodeA.Text} as removed");
lNumOfUpdates++;
}
else if((lNodeAinColB.Parent?.Text ?? "") != (nodeA.Parent?.Text ?? "")) //NodeA exists in Result collection, different parrent -> must be moved
{
W($"Move {nodeA.Text} under {lNodeAinColB.Parent.Text}");
lNumOfUpdates++;
}
}
//Search Result collection, if Original collection does not have nodeB, we must create it (add)
foreach (TreeNode nodeB in colB)
{
if (!colA.Contains(nodeB, new TestNodeEquality()))
{
W($"Add {nodeB.Text}" + ((nodeB.Parent != null)?$" under {nodeB.Parent.Text}":""));
lNumOfUpdates++;
}
}
return lNumOfUpdates;
}
我还没有找到一个适合我的问题,也不是宝贵的资源&我真的想避免重复轮的任何话题。
问题(S):
有现有&工作alghoritm(名称/参考)?什么是这种被称为(Tree Diff/Merge/Lookup/..)的alghorithms/actions?
我可以以任何方式优化alghoritm吗?
@jdweng你能指点我指导文章吗? – Tatranskymedved
如果每个节点都有一个唯一的标识,那么您可以轻松比较它们的状态更改,逐个节点忽略级别,然后应用更改,我想呢? – AKX
https://en.wikipedia.org/wiki/Tree_sort https://en.wikipedia.org/wiki/Binary_search_tree https://en.wikipedia.org/wiki/Self-balancing_binary_search_tree https:// en .wikipedia.org/wiki/Binary_tree https://en.wikipedia.org/wiki/Heapsort – jdweng