在控制台中可以使用哪些算法来绘制二叉树？该树是用 C 实现的。例如，带有数字的 BST：2 3 4 5 8 将在控制台中显示为：
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来自下面的@AnyOneElse Pastbin：
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!Code originally from /http://www.openasthra.com/c-tidbits/printing-binary-trees-in-ascii/
!!! Just saved it, cause the website is down.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Printing Binary Trees in Ascii
Here we are not going to discuss what binary trees are (please refer this, if you are looking for binary search trees), or their operations but printing them in ascii.
The below routine prints tree in ascii for a given Tree representation which contains list of nodes, and node structure is this
struct Tree
{
Tree * left, * right;
int element;
};
This pic illustrates what the below routine does on canvas..
ascii tree
Here is the printing routine..
b5855d39a6b8a2735ddcaa04a404c125001
Auxiliary routines..
//This function prints the given level of the given tree, assuming
//that the node has the given x cordinate.
void print_level(asciinode *node, int x, int level)
{
int i, isleft;
if (node == NULL) return;
isleft = (node->parent_dir == -1);
if (level == 0)
{
for (i=0; i<(x-print_next-((node->lablen-isleft)/2)); i++)
{
printf(" ");
}
print_next += i;
printf("%s", node->label);
print_next += node->lablen;
}
else if (node->edge_length >= level)
{
if (node->left != NULL)
{
for (i=0; i<(x-print_next-(level)); i++)
{
printf(" ");
}
print_next += i;
printf("/");
print_next++;
}
if (node->right != NULL)
{
for (i=0; i<(x-print_next+(level)); i++)
{
printf(" ");
}
print_next += i;
printf("\\");
print_next++;
}
}
else
{
print_level(node->left,
x-node->edge_length-1,
level-node->edge_length-1);
print_level(node->right,
x+node->edge_length+1,
level-node->edge_length-1);
}
}
//This function fills in the edge_length and
//height fields of the specified tree
void compute_edge_lengths(asciinode *node)
{
int h, hmin, i, delta;
if (node == NULL) return;
compute_edge_lengths(node->left);
compute_edge_lengths(node->right);
/* first fill in the edge_length of node */
if (node->right == NULL && node->left == NULL)
{
node->edge_length = 0;
}
else
{
if (node->left != NULL)
{
for (i=0; i<node->left->height && i < MAX_HEIGHT; i++)
{
rprofile[i] = -INFINITY;
}
compute_rprofile(node->left, 0, 0);
hmin = node->left->height;
}
else
{
hmin = 0;
}
if (node->right != NULL)
{
for (i=0; i<node->right->height && i < MAX_HEIGHT; i++)
{
lprofile[i] = INFINITY;
}
compute_lprofile(node->right, 0, 0);
hmin = MIN(node->right->height, hmin);
}
else
{
hmin = 0;
}
delta = 4;
for (i=0; i<hmin; i++)
{
delta = MAX(delta, gap + 1 + rprofile[i] - lprofile[i]);
}
//If the node has two children of height 1, then we allow the
//two leaves to be within 1, instead of 2
if (((node->left != NULL && node->left->height == 1) ||
(node->right != NULL && node->right->height == 1))&&delta>4)
{
delta--;
}
node->edge_length = ((delta+1)/2) - 1;
}
//now fill in the height of node
h = 1;
if (node->left != NULL)
{
h = MAX(node->left->height + node->edge_length + 1, h);
}
if (node->right != NULL)
{
h = MAX(node->right->height + node->edge_length + 1, h);
}
node->height = h;
}
asciinode * build_ascii_tree_recursive(Tree * t)
{
asciinode * node;
if (t == NULL) return NULL;
node = malloc(sizeof(asciinode));
node->left = build_ascii_tree_recursive(t->left);
node->right = build_ascii_tree_recursive(t->right);
if (node->left != NULL)
{
node->left->parent_dir = -1;
}
if (node->right != NULL)
{
node->right->parent_dir = 1;
}
sprintf(node->label, "%d", t->element);
node->lablen = strlen(node->label);
return node;
}
//Copy the tree into the ascii node structre
asciinode * build_ascii_tree(Tree * t)
{
asciinode *node;
if (t == NULL) return NULL;
node = build_ascii_tree_recursive(t);
node->parent_dir = 0;
return node;
}
//Free all the nodes of the given tree
void free_ascii_tree(asciinode *node)
{
if (node == NULL) return;
free_ascii_tree(node->left);
free_ascii_tree(node->right);
free(node);
}
//The following function fills in the lprofile array for the given tree.
//It assumes that the center of the label of the root of this tree
//is located at a position (x,y). It assumes that the edge_length
//fields have been computed for this tree.
void compute_lprofile(asciinode *node, int x, int y)
{
int i, isleft;
if (node == NULL) return;
isleft = (node->parent_dir == -1);
lprofile[y] = MIN(lprofile[y], x-((node->lablen-isleft)/2));
if (node->left != NULL)
{
for (i=1; i <= node->edge_length && y+i < MAX_HEIGHT; i++)
{
lprofile[y+i] = MIN(lprofile[y+i], x-i);
}
}
compute_lprofile(node->left, x-node->edge_length-1, y+node->edge_length+1);
compute_lprofile(node->right, x+node->edge_length+1, y+node->edge_length+1);
}
void compute_rprofile(asciinode *node, int x, int y)
{
int i, notleft;
if (node == NULL) return;
notleft = (node->parent_dir != -1);
rprofile[y] = MAX(rprofile[y], x+((node->lablen-notleft)/2));
if (node->right != NULL)
{
for (i=1; i <= node->edge_length && y+i < MAX_HEIGHT; i++)
{
rprofile[y+i] = MAX(rprofile[y+i], x+i);
}
}
compute_rprofile(node->left, x-node->edge_length-1, y+node->edge_length+1);
compute_rprofile(node->right, x+node->edge_length+1, y+node->edge_length+1);
}
Here is the asciii tree structure…
struct asciinode_struct
{
asciinode * left, * right;
//length of the edge from this node to its children
int edge_length;
int height;
int lablen;
//-1=I am left, 0=I am root, 1=right
int parent_dir;
//max supported unit32 in dec, 10 digits max
char label[11];
};
输出：
2
/ \
/ \
/ \
1 3
/ \ / \
0 7 9 1
/ / \ / \
2 1 0 8 8
/
7
于 2009-04-29T10:42:05.703 回答
51
代码：
int _print_t(tnode *tree, int is_left, int offset, int depth, char s[20][255])
{
char b[20];
int width = 5;
if (!tree) return 0;
sprintf(b, "(%03d)", tree->val);
int left = _print_t(tree->left, 1, offset, depth + 1, s);
int right = _print_t(tree->right, 0, offset + left + width, depth + 1, s);
#ifdef COMPACT
for (int i = 0; i < width; i++)
s[depth][offset + left + i] = b[i];
if (depth && is_left) {
for (int i = 0; i < width + right; i++)
s[depth - 1][offset + left + width/2 + i] = '-';
s[depth - 1][offset + left + width/2] = '.';
} else if (depth && !is_left) {
for (int i = 0; i < left + width; i++)
s[depth - 1][offset - width/2 + i] = '-';
s[depth - 1][offset + left + width/2] = '.';
}
#else
for (int i = 0; i < width; i++)
s[2 * depth][offset + left + i] = b[i];
if (depth && is_left) {
for (int i = 0; i < width + right; i++)
s[2 * depth - 1][offset + left + width/2 + i] = '-';
s[2 * depth - 1][offset + left + width/2] = '+';
s[2 * depth - 1][offset + left + width + right + width/2] = '+';
} else if (depth && !is_left) {
for (int i = 0; i < left + width; i++)
s[2 * depth - 1][offset - width/2 + i] = '-';
s[2 * depth - 1][offset + left + width/2] = '+';
s[2 * depth - 1][offset - width/2 - 1] = '+';
}
#endif
return left + width + right;
}
void print_t(tnode *tree)
{
char s[20][255];
for (int i = 0; i < 20; i++)
sprintf(s[i], "%80s", " ");
_print_t(tree, 0, 0, 0, s);
for (int i = 0; i < 20; i++)
printf("%s\n", s[i]);
}
输出：
.----------------------(006)-------.
.--(001)-------. .--(008)--.
.--(-02) .--(003)-------. (007) (009)
.-------(-06) (002) .--(005)
.--(-08)--. (004)
(-09) (-07)
或者
(006)
+------------------------+---------+
(001) (008)
+----+---------+ +----+----+
(-02) (003) (007) (009)
+----+ +----+---------+
(-06) (002) (005)
+---------+ +----+
(-08) (004)
+----+----+
(-09) (-07)
于 2012-12-07T02:11:58.913 回答
20
一些提示：相同深度的节点之间的间距（例如，您的示例中的 2 和 4 或 3 和 8）是深度的函数。
每个打印行由具有相同深度的所有节点组成，从最左边的节点打印到最右边的节点。
因此，您需要一种方法，例如，根据节点的深度，按照最左边的顺序将节点排列在行数组中。
从根节点开始，广度优先搜索将按照深度和最左边的顺序访问节点。
节点之间的间距可以通过找到树的最大高度来找到，对最深的节点使用一些恒定的宽度，并且对于每个较小的深度将该宽度加倍，这样任何深度的宽度 = ( 1 + maxdepth - currentdepth ) * deepestwidth .
该数字为您提供了每个节点在任何特定深度处的打印“水平宽度”。
左节点水平定位在其父节点宽度的左半部分，右节点位于右半部分。您将为任何没有父节点的节点插入虚拟垫片；一个更简单的方法是确保所有叶子与最深节点的深度相同，其值为空白。显然，您还必须补偿值的宽度，也许通过使最大深度的宽度至少与最大值节点的打印（可能是十进制表示）一样宽。
于 2009-04-29T10:41:22.537 回答
12
这是在数组中实现树时的另一种做法：
#include <stdio.h>
#include <math.h>
#define PARENT(i) ((i-1) / 2)
#define NUM_NODES 15
#define LINE_WIDTH 70
int main() {
int tree[NUM_NODES]={0,1,2,3,4,5,6,7,8,9,1,2,3,4,5};
int print_pos[NUM_NODES];
int i, j, k, pos, x=1, level=0;
print_pos[0] = 0;
for(i=0,j=1; i<NUM_NODES; i++,j++) {
pos = print_pos[PARENT(i)] + (i%2?-1:1)*(LINE_WIDTH/(pow(2,level+1))+1);
for (k=0; k<pos-x; k++) printf("%c",i==0||i%2?' ':'-');
printf("%d",tree[i]);
print_pos[i] = x = pos+1;
if (j==pow(2,level)) {
printf("\n");
level++;
x = 1;
j = 0;
}
}
return 0;
}
输出：
0
1-----------------------------------2
3-----------------4 5-----------------6
7---------8 9---------1 2---------3 4---------5
于 2012-12-07T01:55:35.783 回答
8
我在 c++ 中有这个小解决方案 - 它可以很容易地转换为 c。
我的解决方案确实需要一个补充数据结构来存储当前节点在树中的深度（这是因为如果您正在使用不完整的树，则给定子树的深度可能与它在完整树中的深度不一致。）
#include <iostream>
#include <utility>
#include <algorithm>
#include <list>
namespace tree {
template<typename T>
struct node
{
T data;
node* l;
node* r;
node(T&& data_ = T()) : data(std::move(data_)), l(0), r(0) {}
};
template<typename T>
int max_depth(node<T>* n)
{
if (!n) return 0;
return 1 + std::max(max_depth(n->l), max_depth(n->r));
}
template<typename T>
void prt(node<T>* n)
{
struct node_depth
{
node<T>* n;
int lvl;
node_depth(node<T>* n_, int lvl_) : n(n_), lvl(lvl_) {}
};
int depth = max_depth(n);
char buf[1024];
int last_lvl = 0;
int offset = (1 << depth) - 1;
// using a queue means we perform a breadth first iteration through the tree
std::list<node_depth> q;
q.push_back(node_depth(n, last_lvl));
while (q.size())
{
const node_depth& nd = *q.begin();
// moving to a new level in the tree, output a new line and calculate new offset
if (last_lvl != nd.lvl)
{
std::cout << "\n";
last_lvl = nd.lvl;
offset = (1 << (depth - nd.lvl)) - 1;
}
// output <offset><data><offset>
if (nd.n)
sprintf(buf, " %*s%d%*s", offset, " ", nd.n->data, offset, " ");
else
sprintf(buf, " %*s", offset << 1, " ");
std::cout << buf;
if (nd.n)
{
q.push_back(node_depth(nd.n->l, last_lvl + 1));
q.push_back(node_depth(nd.n->r, last_lvl + 1));
}
q.pop_front();
}
std::cout << "\n";
}
}
int main()
{
typedef tree::node<int> node;
node* head = new node();
head->l = new node(1);
head->r = new node(2);
head->l->l = new node(3);
head->l->r = new node(4);
head->r->l = new node(5);
head->r->r = new node(6);
tree::prt(head);
return 0;
}
它打印出以下内容：
0
1 2
3 4 5 6
于 2011-12-18T10:08:23.513 回答
3
查看 Linux 中 pstree 命令的输出。它不会以您想要的确切形式产生输出，但恕我直言，这种方式更具可读性。
于 2009-04-29T10:59:42.493 回答
3
我赞同 litb 的建议。我最近不得不这样做来打印 Windows 进程的 VAD 树，并且我使用了 DOT 语言（只需从二叉树遍历函数中打印出节点）：
http://en.wikipedia.org/wiki/DOT_language
例如，您的 DOT 文件将包含：
有向图名称 {
5 -> 3;
5 -> 8;
3 -> 4;
3 -> 2;
}
您可以使用 dotty.exe 生成图形或使用 dot.exe 将其转换为 PNG。
于 2009-04-29T14:29:40.117 回答
2
一个非常简单的 C++ 解决方案在水平方向打印树：
5
1
5
9
7
14
代码（Node::print()功能很重要）：
#include<iostream>
using namespace std;
class Tree;
class Node{
public:
Node(int val): _val(val){}
int val(){ return _val; }
void add(Node *temp)
{
if (temp->val() > _val)
{
if (_rchild)
_rchild->add(temp);
else
{
_rchild = temp;
}
}
else
{
if (_lchild)
_lchild->add(temp);
else
{
_lchild = temp;
}
}
}
void print()
{
for (int ix = 0; ix < _level; ++ix) cout << ' ';
cout << _val << endl;
++_level;
if (_lchild)
{
_lchild->print();
--_level;
}
if (_rchild)
{
_rchild->print();
--_level;
}
}
private:
int _val;
Node *_lchild;
Node *_rchild;
static int _level;
};
int Node::_level = 0;
class Tree{
public:
Tree(): _root(0){}
void add(int val)
{
Node *temp = new Node(val);
if (!_root)
_root = temp;
else
_root->add(temp);
}
void print()
{
if (!_root)
return;
_root->print();
}
private:
Node *_root;
};
int main()
{
Tree tree;
tree.add(5);
tree.add(9);
tree.add(1);
tree.add(7);
tree.add(5);
tree.add(14);
tree.print();
}
于 2013-09-07T04:36:57.097 回答
1
我认为您不应该自己编写代码，而是看一下Tree::Visualize，它似乎是一个不错的 Perl 实现，具有不同的可能样式并在那里使用/移植其中一种算法。
于 2009-04-29T10:39:20.890 回答
1
我有一个 Ruby 程序，它计算应该在此处绘制二叉树中每个节点的坐标：http: //hectorcorrea.com/Blog/Drawing-a-Binary-Tree-in-Ruby
这段代码使用一个非常基本的算法来计算坐标，它不是“区域有效的”，但它是一个好的开始。如果您想“实时”查看代码，可以在此处对其进行测试：http: //binarytree.heroku.com/
于 2011-04-11T00:41:37.127 回答