生成一个节点小于100的二叉搜索树。生成后把二叉树变成图存储在Map.txt文件中。

如果想要有序数组的二叉搜索树，则直接把随机生成的数组list1进行排序即可。

代码：

#include<bits/stdc++.h>
using namespace std;
const int N = 100; 

//定义结点结构体
struct Node{
    int val;
    Node *left;
    Node *right;
    int tem1,tem2;
};

Node *Tree;
Node tree[N];
int n,list1[N];
int len;


void array_to_binary_search_tree();
Node *Insert(Node *T,int x); 
Node *creatT();
void showmap(Node *T);
void getWidth(Node *Tree, int depth, int shift, char map[N][N*2]);

int main()
{
    cin>>n;
    for (int i=0;i<n;i++)
    {
        //随机生成一个数字介于(0~1000)之间
        list1[i] = rand() % 999 +1;
    }
    list1[n] = 0;
    array_to_binary_search_tree();

    return 0;
}

//将数组转换为二叉搜索树。
void array_to_binary_search_tree()
{
    len=0;
    for(int i=0;i<N;i++)
    {
        if(list1[i]==0) break;
        else
        {
            Tree=Insert(Tree,list1[i]);
        }
    }
    showmap(Tree);
}

//节点插入函数
Node *Insert(Node *T,int x)
{
    if(!T)                  //节点处为空，创建一个结点
    {
        T = creatT();
        T->val = x;                            //对结点赋值
        return T;                            //返回根结点指针
    }//if
    if (x < T->val)                        //x的权值小于根节点，递归插入左边 
    {
        T->left = Insert(T->left,x);
    }//else if
    if (x > T->val)                          //x的权值大于根节点，递归插入右边 
    {
        T->right = Insert(T->right,x);
    }//else if
    return T;
}

//创建一个节点 
Node *creatT()
{
    tree[len].left=NULL;
    tree[len].right=NULL;
    return &tree[len++];
}

//把二叉树展示在Map.txt中 
void showmap(Node *T)
{
    char graph[N][N*2];
    memset(graph,' ',sizeof graph);
    ofstream r;
    r.open("Map.txt");
    if(!T)
    {
        r<<"空树";
        r.close();
        return ;
    }
    getWidth(T,0,0,graph);
    for (int i=0; i<N; i++)
    {
        int k=N*2-1; 
        while(k>=0 && graph[i][k]==' ')
            k--;
        for(int j=0; j<=k; j++)
        {
            r<<graph[i][j];
        }
        r<<"\n";
    }
}

//得到每一行的宽度
void getWidth(Node *Tree, int depth, int shift, char map[N][N*2])
{
    int i;
    if (Tree->left != NULL)
    {
        getWidth(Tree->left, depth+1, shift, map);
        Tree->tem1 = Tree->left->tem1 + Tree->left->tem2 + 1;
        for (i=(Tree->left->tem1+shift)*2; i<shift*2; i=i+2)
        {
            map[depth*2+1][i]='-';
            map[depth*2+1][i+1]='-';
        }
    }
    else Tree->tem1 = 0;
    if (Tree->right != NULL)
    {
        getWidth(Tree->right, depth+1, shift+Tree->tem1+1, map);
        Tree->tem2 = Tree->right->tem1 + Tree->right->tem2 + 1;
    }
    else Tree->tem2 = 0;

    for (i=shift*2; i<(Tree->tem1+shift)*2; i++)
        map[depth*2][i]=' ';

    map[depth*2][(Tree->tem1+shift)*2]=(char)(Tree->val / 1000 +48);
    map[depth*2][(Tree->tem1+shift)*2+1]=(char)(Tree->val / 100 % 10 +48);
    map[depth*2][(Tree->tem1+shift)*2+2]=(char)(Tree->val / 10 % 10 +48);
    map[depth*2][(Tree->tem1+shift)*2+3]=(char)(Tree->val %10 +48);
    if (Tree->val<1000)
    {
        map[depth*2][(Tree->tem1+shift)*2]=' ';
        if (Tree->val <100)
        {
            map[depth*2][(Tree->tem1+shift)*2+1]=map[depth*2][(Tree->tem1+shift)*2+2];
            map[depth*2][(Tree->tem1+shift)*2+2]=map[depth*2][(Tree->tem1+shift)*2+3];
            map[depth*2][(Tree->tem1+shift)*2+3]=' ';
            if (Tree->val < 10)
                map[depth*2][(Tree->tem1+shift)*2+1]=' ';
        }
    }
    if (Tree->left != NULL)
    {
        map[depth*2+1][(Tree->left->tem1+shift)*2+1]=(char)0xa9;
        map[depth*2+1][(Tree->left->tem1+shift)*2+2]=(char)0xb0;
        map[depth*2+1][(Tree->tem1+shift)*2+1]=(char)0xa9;
        map[depth*2+1][(Tree->tem1+shift)*2+2]=(char)0xbc;
        for (i=(Tree->left->tem1+shift)*2+3; i<(Tree->tem1+shift)*2; i=i+2)
        {
            map[depth*2+1][i]=(char)0xa9;
            map[depth*2+1][i+1]=(char)0xa4;
        }
    }
    if (Tree->right != NULL)
    {
        map[depth*2+1][(Tree->tem1+shift)*2+1]=(char)0xa9;
        map[depth*2+1][(Tree->tem1+shift)*2+2]=(char)0xb8;
        map[depth*2+1][(Tree->tem1+Tree->right->tem1+shift)*2+3]=(char)0xa9;
        map[depth*2+1][(Tree->tem1+Tree->right->tem1+shift)*2+4]=(char)0xb4;
        for (i=(Tree->tem1+shift)*2+3; i<(Tree->tem1+Tree->right->tem1+shift)*2+2; i=i+2)
        {
            map[depth*2+1][i]=(char)0xa9;
            map[depth*2+1][i+1]=(char)0xa4;
        }
    }
    if (Tree->left != NULL && Tree->right != NULL)
    {
        map[depth*2+1][(Tree->tem1+shift)*2+1]=(char)0xa9;
        map[depth*2+1][(Tree->tem1+shift)*2+2]=(char)0xd8;
    }
}