C How to "draw" a Binary Tree to the console [closed]

Question

What algorithms can be used to draw a binary tree in the console? The tree is implemented in C. For example, a BST with numbers: 2 3 4 5 8 would be shown in the console as:

Answer 1

Check out Printing Binary Trees in Ascii

From @AnyOneElse Pastbin below:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!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];       }; 

output:

        2        / \       /   \      /     \     1       3    / \     / \   0   7   9   1  /   / \     / \ 2   1   0   8   8        /       7