Merge pull request wangzheng0822#255 from suidongliang/master

binarysearchtree

c-cpp/24_binarysearchtree/binary_search_tree.cpp

@@ -0,0 +1,268 @@
+#include <iostream>
+
+using namespace std;
+
+typedef int DataType;
+
+struct tree_node
+{
+	DataType data;
+	tree_node* left=NULL;
+	tree_node* right=NULL;
+};
+
+class binary_search_tree{
+private:
+	tree_node* root;
+	int num;
+public:
+	binary_search_tree() :num(0)
+	{
+		root = new tree_node;
+		root->left = NULL;
+		root->right = NULL;
+	}
+
+	bool find(DataType it,tree_node* root)
+	{
+		if (NULL == root)return false;
+		if (it == root->data) {
+			return true;
+		}
+		else if (it > root->data)
+		{
+			return find(it, root->right);
+		}
+		else
+		{
+			return find(it, root->left);
+		}
+	}
+
+	bool find_data(DataType it)
+	{
+		return find(it, root);
+		/*
+		tree_node* p = root;
+		while (p != NULL)
+		{
+			if (it < p->data)p = p->left;
+			else if (it>p->data)p = p->right;
+			else return true;
+		}
+		return false;
+		*/
+	}
+
+
+	void insert_data(DataType it)
+	{
+
+		if (0==num)
+		{
+			root->data = it;
+			num++;
+			return;
+		}
+		tree_node* p = root;
+		while (p != NULL)
+		{
+			if (it < p->data)
+			{
+				if (NULL == p->left)
+				{
+					p->left = new tree_node;
+					p->left->data = it;
+					num++;
+					return;
+				}
+				p = p->left;
+			}
+			else
+			{
+				if (NULL == p->right)
+				{
+					p->right = new tree_node;
+					p->right->data = it;
+					num++;
+					return;
+				}
+				p = p->right;
+			}
+		}
+
+	}
+
+	void delet(DataType it)
+	{
+		if (NULL == root)return;
+		tree_node* p = root;
+		tree_node* pp = NULL;//pp记录的是p的父节点
+		while (p != NULL&&p->data != it)
+		{
+			pp = p;
+			if (it > p->data)p = p->right;
+			else
+				p = p->left;
+		}
+		if (p == NULL)return;//没有找到
+		//删除的节点有两个子节点
+		if (p->left != NULL&&p->right != NULL)
+		{
+			tree_node* minP = p->right;
+			tree_node* minPP = p;//记录P的父节点
+			while (minP->left != NULL)//寻找右子树最小节点
+			{
+				minPP = minP;
+				minP = minP->left;
+			}
+			p->data = minP->data;//将minP替换到p中
+			//将p换到叶节点上，使用叶节点方法进行删除
+			p = minP;
+			pp = minPP;
+		}
+
+		//删除节点是叶节点或者是仅有一个节点
+		tree_node* child;
+		if (p->left != NULL) child = p->left;
+		else if (p->right != NULL) child = p->right;
+		else child = NULL;
+
+		if (NULL == pp) root = child;//删除的是根节点
+		else if (p == pp->left)pp->left = child;
+		else pp->right = child;
+	}
+
+	DataType get_max()
+	{
+		if (NULL == root)return NULL;
+		tree_node* tmp=root;
+		while (tmp->right != NULL)
+		{
+			tmp = tmp->right;
+		}
+		return tmp->data;
+	}
+	DataType get_min()
+	{
+		if (NULL == root)return NULL;
+		tree_node* tmp=root;
+		while (tmp->left != NULL)
+		{
+			tmp = tmp->left;
+		}
+		return tmp->data;
+	}
+
+	DataType get_prenode(DataType it)
+	{
+		if (NULL == root)return NULL;
+		if (it == root->data) return NULL;
+		tree_node* p=root;
+		tree_node* pp=NULL;
+		while ((p->data != it)&&(p!=NULL))
+		{
+			pp = p;
+			if (p->data < it)
+			{
+				p=p->right;
+			}
+			else
+			{
+				p = p->left;
+			}
+		}
+		return ((NULL==p)?NULL:pp->data);
+	}
+
+	DataType get_postnode(DataType it)
+	{
+		if (NULL == root)return -1;
+		tree_node* p = root;
+		while ((p->data != it) && (p != NULL))
+		{
+			if (p->data < it)
+			{
+				p = p->left;
+			}
+			else
+			{
+				p = p->right;
+			}
+		}
+		if (NULL == p)
+		{
+			return -1;
+		}
+		else if (p->left!=NULL)
+		{
+			return p->left->data;
+		}
+		else if (p->right!=-NULL)
+		{
+			return p->right->data;
+		}
+		else
+		{
+			return NULL;
+		}
+	}
+
+	void mid_order(tree_node* rt)
+	{
+		if (NULL == rt)return;
+		mid_order(rt->left);
+		cout << rt->data;
+		mid_order(rt->right);
+	}
+	void order()
+	{
+		if (NULL == root)return;
+		return mid_order(root);
+	}
+
+	int get_high(tree_node* rt)
+	{
+		int lhigh = 0;
+		int rhigh = 0;
+		if (NULL == rt)return 0;
+		lhigh = get_high(rt->left);
+		rhigh = get_high(rt->right);
+		return ((lhigh > rhigh) ? (lhigh + 1) : (rhigh + 1));
+	}
+
+	int high()
+	{
+		if (NULL == root) return 1;
+		return get_high(root);
+	}
+};
+
+int main()
+{
+	binary_search_tree my_tree;
+
+	my_tree.insert_data(5);
+	my_tree.insert_data(4);
+	my_tree.insert_data(6);
+	my_tree.insert_data(10);
+	my_tree.insert_data(3);
+	my_tree.insert_data(8);
+	my_tree.insert_data(1);
+	if (my_tree.find_data(3))
+	{
+		cout << "找到了数字3" << endl;
+	}
+	else
+	{
+		cout << "没有找到数字3" << endl;
+	}
+	my_tree.delet(4);
+	cout << "Max" << my_tree.get_max() << endl;
+	cout << "Min" << my_tree.get_min() << endl;
+	cout << "pre node of 5 is " <<my_tree.get_prenode(5) <<endl;
+	cout << "post node of 5 is " << my_tree.get_postnode(5) << endl;
+	my_tree.order();
+	cout << "high of tree is " << my_tree.high() << endl;
+	return 0;
+}