多路搜索树的初始化实现

MTree.h

#pragma once
#include <vector>

using namespace std;

//节点的关键字和子节点的指针对是
//p0 p1 p2 ... p(n-1) pn
//k0 k1 k2 ... k(n-1)
//而不是象教材里的
//p0 p1 p2 ... p(n-1) pn
//   k1 k2 ... k(n-1) kn
template <typename T>
class MTreeNode
{
public:
    MTreeNode(int _m_routeCount) : m_routeCount(_m_routeCount) {
        m_keyNumber = 0;
        pChildsArray = new MTreeNode<T>*[m_routeCount];
        keys = new T[m_routeCount - 1];

        for (int i = 0; i < m_routeCount; ++i) {
            pChildsArray[i] = NULL;
            if (i != m_routeCount - 2)
                keys[i] = 0;
        }
    }

    virtual ~MTreeNode() {
        delete[] pChildsArray;
        delete[] keys;
    }

    MTreeNode<T>** pChildsArray;
    T* keys;
    int m_keyNumber;
    int m_routeCount;
};

//多路搜索树
template <typename T>
class MTree {
public:
    int RouteCount;
    MTreeNode<T>* Root;

    void AddValue(MTreeNode<T>* &tmpNode, T t) {
        if (tmpNode == NULL) {
            tmpNode = new MTreeNode<T>(RouteCount);
        }

        int pindex = 0;
        //默认插入到当前节点的某个关键字里
        bool bInsertIntoChildNode = false;
        for (int i = 0; i < tmpNode->m_keyNumber; ++i) {
            if (t < tmpNode->keys[i]) {
                pindex = i;
                //如果要插入的值小于当前节点的某个关键字，则插入到子节点里
                bInsertIntoChildNode = true;
                break;
            } else {
                pindex = i + 1;               
            }
        }

        //tmpNode的关键码未存完，存在tmpNode的索引为tmpNode->m_keyNumber的关键字里
        if (!bInsertIntoChildNode && tmpNode->m_keyNumber < tmpNode->m_routeCount - 1) {
            tmpNode->keys[tmpNode->m_keyNumber++] = t;
        } else {
            //存在tmpNode->pChildsArray[pindex]所指的节点里
            if (tmpNode->pChildsArray[pindex] == NULL)
                tmpNode->pChildsArray[pindex] = new MTreeNode<T>(RouteCount);
            AddValue(tmpNode->pChildsArray[pindex], t);
        }
    }

    /*void AddValue(MTreeNode<T>* &tmpNode, T t) {
        if (tmpNode == NULL) {
            tmpNode = new MTreeNode<T>(RouteCount);
        }

        //根节点关键字未满
        if (tmpNode->m_keyNumber < RouteCount - 1) {
            //while (tmpNode->m_keyNumber < RouteCount - 1) {
            tmpNode->keys[tmpNode->m_keyNumber++] = t;
            //}
        } else {
            int pindex = 0;
            for (int i = 0; i < tmpNode->m_keyNumber; ++i) {
                if (t < tmpNode->keys[i]) {
                    pindex = i;
                    break;
                } else{
                    pindex = tmpNode->m_routeCount - 1;
                }
            }

            if (tmpNode->pChildsArray[pindex] == NULL)
                tmpNode->pChildsArray[pindex] = new MTreeNode<T>(RouteCount);
            AddValue(tmpNode->pChildsArray[pindex], t);
        }
    }*/
};

 

 

MTreeDemo.cpp

#include "stdafx.h"
#include "MTree.h"

int _tmain(int argc, _TCHAR* argv[])
{
    MTree<int> *root = new MTree<int>();
    root->RouteCount = 3;
    root->AddValue(root->Root, 18);
    root->AddValue(root->Root, 42);
    root->AddValue(root->Root, 8);
    root->AddValue(root->Root, 14);
    root->AddValue(root->Root, 22);
    root->AddValue(root->Root, 29);
    root->AddValue(root->Root, 44);
    root->AddValue(root->Root, 52);
    root->AddValue(root->Root, 20);
    root->AddValue(root->Root, 33);
    return 0;
}