How to print in console a tree horizontally with links using c

Question

I'm reposting my question (obviously not enough information). I'd like to print a given binary tree horizontally in C with links between nodes. I've done it without links; when I tried to do it with links it really got messed up.

PS: More explanations in the images Click here to view and here's the structure I work with:

typedef struct node{
   int val;            // value of the node
   struct node *left;  // left node
   struct node *right; // right node
}node;

And here's the function I wrote that can draw the tree with blanks and no links between nodes:

#define space 5

//secondary function
void draw_tree_hor2(node *tree, int distance)
{
    // stopping condition
    if (tree== NULL)
        return;

    // increase spacing
    distance += space;

    // start with right node
    draw_tree_hor2(tree->right, distance);

    // print root after spacing

    printf("\n");

    for (int i = space; i < distance; i++)
        printf(" ");

    printf("%d\n", tree->value);

    // go to left node
    draw_tree_hor2(tree->left, distance);
}

//primary fuction
void draw_tree_hor(node *tree)
{
   //initial distance is 0
    draw_tree_hor2(tree, 0);
}

If the information that i gave aren't enough please tell me...

Answer 1

I threw something together real quick, seems to work. Might want to add some checks to prevent depth from exceeding path size etc. Should get you started at least.

#include <stdio.h>

#define space 5


typedef struct node{
   int value;          // value of the node
   struct node *left;  // left node
   struct node *right; // right node
}node;

//secondary function
void draw_tree_hor2(node *tree, int depth, char *path, int right)
{
    // stopping condition
    if (tree== NULL)
        return;

    // increase spacing
    depth++;

    // start with right node
    draw_tree_hor2(tree->right, depth, path, 1);

    if(depth > 1)
    {
        // set | draw map
        path[depth-2] = 0;

        if(right)
            path[depth-2] = 1;
    }

    if(tree->left)
        path[depth-1] = 1;

    // print root after spacing
    printf("\n");

    for(int i=0; i<depth-1; i++)
    {
      if(i == depth-2)
          printf("+");
      else if(path[i])
          printf("|");
      else
          printf(" ");

      for(int j=1; j<space; j++)
      if(i < depth-2)
          printf(" ");
      else
          printf("-");
    }

    printf("%d\n", tree->value);

    // vertical spacers below
    for(int i=0; i<depth; i++)
    {
      if(path[i])
          printf("|");
      else
          printf(" ");

      for(int j=1; j<space; j++)
          printf(" ");
    }

    // go to left node
    draw_tree_hor2(tree->left, depth, path, 0);
}

//primary fuction
void draw_tree_hor(node *tree)
{
    // should check if we don't exceed this somehow..
    char path[255] = {};

    //initial depth is 0
    draw_tree_hor2(tree, 0, path, 0);
}



node n1, n2, n3, n4, n5, n6, n7;

int main()
{
  n1.value = 1;
  n2.value = 2;
  n3.value = 3;
  n4.value = 4;
  n5.value = 5;
  n6.value = 6;
  n7.value = 7;

  n1.right = &n2;
  n1.left = &n3;
  //n2.right = &n4;
  //n2.left = &n5;
  n3.right = &n6;
  n3.left = &n7;

  n2.right = &n3;
  n2.left = &n3;

  draw_tree_hor(&n1);

  return 0;
}

Output:

>gcc test_graph.c && a

          +----6
          |
     +----3
     |    |
     |    +----7
     |
+----2
|    |
|    |    +----6
|    |    |
|    +----3
|         |
|         +----7
|
1
|
|    +----6
|    |
+----3
     |
     +----7