重建二叉树

来源：互联网发布：页面加载完成后执行js 编辑：程序博客网时间：2024/05/21 17:51
这里写图片描述
#define  _CRT_SECURE_NO_WARNINGS#include<iostream>using namespace std;struct BinaryTreeNode{    int _value;    BinaryTreeNode* _left;    BinaryTreeNode* _right;    BinaryTreeNode(int value)        :_value(value),        _left(NULL),        _right(NULL)    {}};class BinaryTree{    typedef BinaryTreeNode Node;public:    BinaryTree()        :_root(NULL)    {}    void Construct(int *prevorder, int *inorder, int length)    {        if (prevorder == NULL || inorder == NULL || length <= 0)        {            return;        }        _root = _Construct(prevorder, prevorder + length - 1, inorder, inorder + length - 1);    }    void PrePrint()    {        _PrevPrint(_root);        cout << endl;    }    void InPrint()    {        _InPrint(_root);        cout << endl;    }protected:    Node* _Construct(int *startPrevorder, int *endPrevorder, int *startInorder, int *endInorder)    {        int rootValue = startPrevorder[0];        Node* root = new Node(rootValue);        if (startPrevorder == endPrevorder)        {            if (startInorder == endInorder)            {                return root;            }            else            {                throw exception("Invalid input");            }        }        /*        在中序遍历中找根节点        */        int* rootInorder = startInorder;          while (rootInorder <= endInorder && *rootInorder != rootValue)        {            ++rootInorder;        }        /*没找到，抛个异常*/        if (*rootInorder != rootValue)        {            throw exception("Invalid input");        }        int leftLength = rootInorder - startInorder;        int *leftPrevOrderEnd = startPrevorder + leftLength;        if (leftLength > 0)        {//构建做子树            root->_left = _Construct(startPrevorder + 1, leftPrevOrderEnd, startInorder, rootInorder - 1);        }        if (leftLength < endPrevorder - startPrevorder)        {            //构建右子树            root->_right = _Construct(leftPrevOrderEnd + 1, endPrevorder, rootInorder + 1, endInorder);        }        return root;    }    void _InPrint(Node* root)    {        if (root == NULL)        {            return;        }        _PrevPrint(root->_left);        cout << root->_value << " ";        _PrevPrint(root->_right);    }    void _PrevPrint(Node* root)    {        if (root == NULL)        {            return;        }        cout << root->_value << " ";        _PrevPrint(root->_left);        _PrevPrint(root->_right);    }private:    Node* _root;};void test(){    int prev[] = { 1, 0, 4, 7, 3, 5, 6, 8 };    int in[] = { 4, 7, 2, 1, 5, 3, 8, 6 };    BinaryTree t;    t.Construct(prev, in, 8);    t.PrePrint();    t.InPrint();}int main(){    test();    system("pause");    return 0;}
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