dsa/week13/printTree.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "AVL.h"

//printing tree in ascii

typedef struct asciinode_struct asciinode;

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];
};

#define MAX_HEIGHT 1000
int lprofile[MAX_HEIGHT];
int rprofile[MAX_HEIGHT];
#define INFINITY (1 << 20)

//adjust gap between left and right nodes
int gap = 3;

//used for printing next node in the same level,
//this is the x coordinate of the next char printed
int print_next;

int MIN(int X, int Y)
{
  return ((X) < (Y)) ? (X) : (Y);
}

int MAX(int X, int Y)
{
  return ((X) > (Y)) ? (X) : (Y);
}

asciinode *build_ascii_tree_recursive(Node *t)
{
  asciinode *node;

  if (t == NULL)
    return NULL;

  node = (asciinode *)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|%d", t->key, t->height);

  node->lablen = strlen(node->label);

  return node;
}

//Copy the tree into the ascii node structre
asciinode *build_ascii_tree(Node *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);
}

//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;
}

//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);
  }
}

//prints ascii tree for given Node structure
void printTree(Node *root)
{
  asciinode *proot;
  int xmin, i;
  if (root == NULL)
    return;
  proot = build_ascii_tree(root);
  compute_edge_lengths(proot);
  for (i = 0; i < proot->height && i < MAX_HEIGHT; i++)
  {
    lprofile[i] = INFINITY;
  }
  compute_lprofile(proot, 0, 0);
  xmin = 0;
  for (i = 0; i < proot->height && i < MAX_HEIGHT; i++)
  {
    xmin = MIN(xmin, lprofile[i]);
  }
  for (i = 0; i < proot->height; i++)
  {
    print_next = 0;
    print_level(proot, -xmin, i);
    printf("\n");
  }
  if (proot->height >= MAX_HEIGHT)
  {
    printf("(This tree is taller than %d, and may be drawn incorrectly.)\n", MAX_HEIGHT);
  }
  free_ascii_tree(proot);
}