二叉查找树的实现(BST)

来源：互联网发布：张伟华知乎编辑：程序博客网时间：2024/05/16 01:47

用C风格写的代码，可能用模块写更有利于应用。不过在C++里有map,set之类的容器，也不愿再去折腾了。

Demo

```
#ifndef __BINARY_SEARCH_TREE_H
```
```
#define __BINARY_SEARCH_TREE_H
```
```
#include
```
```
namespace dskit
```
```
{    typedef int ELEMENTSTYPE;
```
```
    typedef struct BSTNode
```
```
    {
```
```
        ELEMENTSTYPE value;
```
```
        struct BSTNode* left;
```
```
        struct BSTNode* right;
```
```
    }BSTNODE;
```

    typedef BSTNODE* binary_search_tree;

    binary_search_tree Insert(ELEMENTSTYPE x, binary_search_tree& bstTree);

    binary_search_tree Delete(ELEMENTSTYPE x, binary_search_tree bstTree);

    BSTNODE* Find(ELEMENTSTYPE x, binary_search_tree bstTree);

```
}
```
```
#endif
```

.src_container{background-color:#e7e5dc; width:99%; overflow:hidden; margin:12px 0 12px 0 !important; padding:0px 3px 3px 0px}.src_container .titlebar{ background-color:#d4dfff; border:1px solid #4f81bd; border-bottom:0; padding:3px 24px; margin:0; width:auto; line-height:120%; overflow:hidden; text-align:left; font-size:12px}.src_container .toolbar{ display:inline; font-weight:normal; font-size:100%; float:right; cursor:hand; color:#00f; text-align:left; overflow:hidden}.toolbar span.button{ display:inline; font-weight:normal; font-size:100%; cursor:hand; color:#00f; text-align:left; overflow:hidden; cursor:pointer;}.src_container div.clientarea{ background-color:white; border:1px solid #4f81bd; margin:0; width:auto !important; width:100%; height:auto; overflow:auto; text-align:left; font-size:12px; font-family: "Courier New","Consolas","Fixedsys",courier,monospace,serif}.src_container ol.mainarea{ padding:0 0 0 52px; margin:0; background-color:#f7f7ff !important}.number_show{ padding-left:52px !important; list-style:decimal outside !important}.number_show li{ list-style:decimal outside !important; border-left:1px dotted #4f81bd}.number_hide{ padding-left:0px !important; list-style-type:none !important}.number_hide li{ list-style-type:none !important; border-left:0px}ol.mainarea li{ display:list-item !important; font-size:12px !important; margin:0 !important; line-height:18px !important; padding:0 0 0 0px !important; background-color:#f7f7ff !important; color:#4f81bd}ol.mainarea li pre{color:black; line-height:18px; padding:0 0 0 12px !important; margin:0em; background-color:#fff !important}.linewrap ol.mainarea li pre{white-space:pre-wrap; white-space:-moz-pre-wrapwhite-space:-pre-wrap; white-space:-o-pre-wrap; word-wrap:break-word}ol.mainarea li pre.alt{ background-color:#f7f7ff !important}

Demo

```
#include "binary_search_tree.h"
```
```
namespace dskit{
```

binary_search_tree Insert(ELEMENTSTYPE x, binary_search_tree& bstTree)

```
{
```
```
    if(NULL == bstTree)
```
```
    {
```
```
        bstTree= new BSTNODE;
```
```
        if(NULL != bstTree)
```
```
        {
```
```
            bstTree->value = x;
```
```
            bstTree->left = NULL;
```
```
            bstTree->right = NULL;
```
```
        }
```
```
    }
```
```
    else
```
```
    {
```
```
        if(x < bstTree->value)
```
```
        {
```
```
            Insert(x, bstTree->left);
```
```
        }
```
```
        else if(x > bstTree->value)
```
```
        {    
```
```
            Insert(x, bstTree->right);
```
```
        }
```
```
    }
```
```
    return bstTree;
```
```
}
```

BSTNODE* Find(ELEMENTSTYPE x, binary_search_tree bstTree)

```
{
```
```
    printf("find/n");
```
```
    if(NULL == bstTree)
```
```
    {
```
```
        return NULL;
```
```
    }
```
```
    if(x < bstTree->value)
```
```
    {
```
```
        return Find(x, bstTree->left);
```
```
    }
```
```
    else if (x > bstTree->value)
```
```
    {
```
```
        return Find(x, bstTree->right);
```
```
    }
```
```
    else
```
```
        return bstTree;
```
```
}
```

BSTNODE* find_min(binary_search_tree bstTree)

```
{
```
```
    if(NULL == bstTree)
```
```
    {
```
```
        return NULL;
```
```
    }
```
```
    else if(NULL == bstTree->left)
```
```
    {
```
```
        return bstTree;
```
```
    }
```
```
    else
```
```
    {
```
```
        return find_min(bstTree->left);
```
```
    }
```
```
}
```

binary_search_tree Delete(ELEMENTSTYPE x, binary_search_tree bstTree)

```
{
```
```
    if(NULL == bstTree)
```
```
    {
```
```
        return bstTree;
```
```
    }
```
```
    else
```
```
    {
```
```
        if(x < bstTree->value)
```
```
        {
```
```
            Delete(x, bstTree->left);
```
```
        }
```
```
        else if(x > bstTree->value)
```
```
        {
```
```
            Delete(x, bstTree->right);
```
```
        }
```
```
        else
```
```
        {
```

            if(NULL != bstTree->left && NULL != bstTree->right)

```
            {
```

                BSTNODE* temp = find_min(bstTree->right);

                bstTree->value = temp->value;

                bstTree->right = Delete(temp->value, bstTree->right);

```
            }
```
```
            else
```
```
            {
```

                BSTNODE* temp = bstTree;

                if(NULL == bstTree->left)

```
                {
```

                    bstTree = bstTree->right;

```
                }
```

                else if(NULL == bstTree->right)

```
                {
```

                    bstTree = bstTree->left;

```
                }
```
```
                delete temp;
```
```
            }
```
```
        }
```
```
    }
```
```
    return bstTree;
```
```
}
```
```
}
```
```
int main(int argc, char* argv[])
```
```
{
```
```
    using namespace dskit;
```
```
    binary_search_tree bstTree = NULL;
```
```
    
```
```
    Insert(1, bstTree);
```
```
    printf("start find./n");
```
```
    if(Find(1, bstTree))
```
```
    {
```
```
        printf("found./n");
```
```
    }
```
```
    if(!Find(2, bstTree))
```
```
    {
```
```
        printf("not found./n");
```
```
    }
```
```
    return 0;
```
```
}
```