# Types of Views & Binary Trees

In binary trees, the views and types refer to different perspectives and classifications of the tree structure.

##### Types of Views in Binary Tree are :
``````                     1
/   \
2       3
/ \     / \
4   5   6   7
/ \   \     /
8   9   10  11
``````
• Horizontal View: The horizontal view of a binary tree shows the nodes from left to right at each level. Nodes at the same level are listed in the order of their appearance, from left to right.
``1 2 3 4 5 6 7 8 9 10 11``
• Vertical View: The vertical view of a binary tree shows the nodes from top to bottom, where nodes in the same vertical line are displayed in the order of their occurrence from top to bottom.
``````8
4
2 9 10
1 5 6 11
3 7``````
• Left View: The left view of a binary tree shows the leftmost node at each level. It represents the visible nodes when looking at the tree from the left side.
``1 2 4 8``
• Right View: The right view of a binary tree shows the rightmost node at each level. It represents the visible nodes when looking at the tree from the right side.
``1 3 7 11``
• Top View: The top view of a binary tree displays the nodes visible when viewing the tree from the top. It shows the nodes on the vertical lines that intersect the topmost node at each horizontal distance.
``8 4 2 1 3 7 11``
• Bottom View: The bottom view of a binary tree displays the nodes visible when viewing the tree from the bottom. It shows the nodes on the vertical lines that intersect the bottom-most node at each horizontal distance.
``8 9 10 5 6 11 7``
##### Types of Binary Trees:
• Full Binary Tree: A binary tree in which every node has either 0 or 2 children.
``````        1
/ \
2   3
/ \
4   5
``````
• Complete Binary Tree: A binary tree in which all levels, except possibly the last one, are completely filled, and all nodes are as left as possible.
``````        1
/ \
2   3
/ \  /
4   5 6``````
• Perfect Binary Tree: A binary tree in which all internal nodes have two children, and all leaf nodes are at the same level.
``````        1
/ \
2   3
/ \ / \
4  5 6  7``````
• Balanced Binary Tree: A binary tree in which the heights of the left and right subtrees of every node differ by at most one.
``````        1
/ \
2   3
/     \
4       5
``````
• Binary Search Tree (BST): A binary tree in which for every node, all values in its left subtree are less than its value, and all values in its right subtree are greater than its value.
``````        4
/ \
2   5
/ \   \
1   3   6
``````
• Skewed Binary Tree: is a special type of binary tree in which all the nodes are either in the left subtree or the right subtree.
``````         1
/
2
/
3
/
4

OR

1
\
2
\
3
\
4
``````