Binary sort tree的C#实现

1. 定义:

    public class BinarySortTree<T> where T : IComparable
    {
        public T Data { set; get; }
        public BinarySortTree<T> LeftChild { set; get; }
        public BinarySortTree<T> RightChild { set; get; }

        private BinarySortTree()
        {
        }
    }

2. 创建:

        #region Create a new binary sort tree
        public static BinarySortTree<T> Create(T[] dataList)
        {
            if (dataList == null || dataList.Count() < 1)
            {
                return null;
            }

            BinarySortTree<T> tree = new BinarySortTree<T>
            {
                Data = dataList[0]
            };
            for (int i = 1; i < dataList.Length; i++)
            {
                InsertNode(tree, dataList[i]);
            }

            return tree;
        }

        private static void InsertNode(BinarySortTree<T> tree, T data)
        {
            if (tree == null)
            {
                tree = new BinarySortTree<T>
                {
                    Data = data
                };
                return;
            }

            BinarySortTree<T> node = tree;
            do
            {
                if (data.CompareTo(node.Data) < 0)
                {
                    if (node.LeftChild == null)
                    {
                        node.LeftChild = new BinarySortTree<T>
                        {
                            Data = data
                        };
                        return;
                    }
                    else
                    {
                        node = node.LeftChild;
                    }
                }
                else
                {
                    if (node.RightChild == null)
                    {
                        node.RightChild = new BinarySortTree<T>
                        {
                            Data = data
                        };
                        return;
                    }
                    else
                    {
                        node = node.RightChild;
                    }
                }
            } while (node != null);
        }
        #endregion

3. 插入新节点:

        /// <summary>
        /// insert a node
        /// </summary>
        /// <param name="data"></param>
        public void InsertNode(T data)
        {
            BinarySortTree<T> node = this;
            do
            {
                if (data.CompareTo(node.Data) < 0)
                {
                    if (node.LeftChild == null)
                    {
                        node.LeftChild = new BinarySortTree<T>
                        {
                            Data = data
                        };
                        return;
                    }
                    else
                    {
                        node = node.LeftChild;
                    }
                }
                else
                {
                    if (node.RightChild == null)
                    {
                        node.RightChild = new BinarySortTree<T>
                        {
                            Data = data
                        };
                        return;
                    }
                    else
                    {
                        node = node.RightChild;
                    }
                }
            } while (node != null);
        }

4. search:

        /// <summary>
        /// Search the node of whose Data equal to data
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public BinarySortTree<T> Search(T data)
        {
            BinarySortTree<T> node = this;
            do
            {
                if (data.CompareTo(node.Data) == 0)
                {
                    return node;
                }
                else
                {
                    if (data.CompareTo(node.Data) < 0)
                    {
                        if (node.LeftChild == null)
                        {
                            break;
                        }
                        else
                        {
                            node = node.LeftChild;
                        }
                    }
                    else
                    {
                        if (node.RightChild == null)
                        {
                            break;
                        }
                        else
                        {
                            node = node.RightChild;
                        }
                    }
                }
            } while (node != null);

            return null;
        }

5. 删除节点:

        /// <summary>
        /// Remove the node of whose data equal to data from binary sort tree
        /// </summary>
        /// <param name="data"></param>
        public static void Remove(BinarySortTree<T> tree, T data)
        {
            if (tree == null)
                return;

            // if equal to root node
            BinarySortTree<T> node = tree;
            if (data.CompareTo(node.Data) == 0)
            {
                if (node.LeftChild == null)
                {
                    tree = node.RightChild;
                }
                else
                {
                    if (node.RightChild == null)
                    {
                        tree = node.LeftChild;
                    }
                    else
                    {
                        BinarySortTree<T> minParentNode = node;
                        BinarySortTree<T> minNode = node.RightChild;
                        while (minNode.RightChild != null)
                        {
                            minParentNode = minNode;
                            minNode = minNode.RightChild;
                        }
                        minNode.LeftChild = node.LeftChild;
                        minNode.RightChild = minNode.Equals(node.RightChild) ? null : node.RightChild;
                        minParentNode.LeftChild = null;

                        tree = minNode;
                    }
                }

                return;
            }

            // don't equal to root node
            BinarySortTree<T> parentNode = tree;
            bool isLeft = true;
            do
            {
                // equal to current node
                if (data.CompareTo(node.Data) == 0)
                {
                    if (node.LeftChild == null)
                    {
                        node = node.RightChild;
                    }
                    else
                    {
                        if (node.RightChild == null)
                        {
                            node = node.LeftChild;
                        }
                        else
                        {
                            BinarySortTree<T> minParentNode = node;
                            BinarySortTree<T> minNode = node.RightChild;
                            while (minNode.LeftChild != null)
                            {
                                minParentNode = minNode;
                                minNode = minNode.LeftChild;
                            }
                            minNode.LeftChild = node.LeftChild;
                            minNode.RightChild = node.RightChild;
                            minParentNode.LeftChild = null;

                            node = minNode;
                        }
                    }

                    if (isLeft)
                        parentNode.LeftChild = node;
                    else
                        parentNode.RightChild = node;

                    return;
                }
                else
                {
                    if (data.CompareTo(node.Data) < 0)
                    {
                        if (node.LeftChild == null)
                            return;
                        else
                        {
                            parentNode = node;
                            node = node.LeftChild;
                            isLeft = true;
                        }
                    }
                    else
                    {
                        if (node.RightChild == null)
                            return;
                        else
                        {
                            parentNode = node;
                            node = node.RightChild;
                            isLeft = false;
                        }
                    }
                }
            } while (node != null);
        }

 6. 测试:

            BinarySortTree<int> tree = BinarySortTree<int>.Create(new int[]{5, 10, 5, 20, 17, 12, 19, 2});
            tree.InsertNode(1);
            tree.InsertNode(0);
            BinarySortTree<int> node = tree.Search(1);
            TreeAction<int>.Remove(tree, 10);

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