Overview of Binary Tree
⛳ Overview
Binary Tree is an important data structure, and it's widely used in BFS, DFS, DP, Back tracking, Divide and conquer algorithms.
📃 Analysis
tip
3 Tree Traversals
- Inorder: Left, Root, Right
- Preorder: Root, Left, Right
- Postorder: Left, Right,Root
Examples:
Inorder: 4 2 5 6 3 7 1
Preorder: 1 2 4 5 3 6 7
PostOrder: 4 5 2 6 7 3 1
✏ Code Editor
1. Print the level of each node
Live Editor
Result
Total test cases: 1
Input: "{ "val": 1, "left": { "val": 2, "left": { "val": 4, "left": null, "right": null }, "right": { "val": 5, "left": null, "right": null } }, "right": { "val": 3, "left": { "val": 6, "left": null, "right": null }, "right": { "val": 7, "left": null, "right": null } } }" Output: " { "1": { "node": { "val": 1, "left": { "val": 2, "left": { "val": 4, "left": null, "right": null }, "right": { "val": 5, "left": null, "right": null } }, "right": { "val": 3, "left": { "val": 6, "left": null, "right": null }, "right": { "val": 7, "left": null, "right": null } } }, "depth": 1 }, "2": { "node": { "val": 3, "left": { "val": 6, "left": null, "right": null }, "right": { "val": 7, "left": null, "right": null } }, "depth": 2 }, "3": { "node": { "val": 7, "left": null, "right": null }, "depth": 3 } }"
2. Print the number of leafs of each node
Live Editor
Result
Total test cases: 1
Input: "{ "val": 1, "left": { "val": 2, "left": { "val": 4, "left": null, "right": null }, "right": { "val": 5, "left": null, "right": null } }, "right": { "val": 3, "left": { "val": 6, "left": null, "right": null }, "right": { "val": 7, "left": null, "right": null } } }" Output: "7 { "1": { "node": { "val": 1, "left": { "val": 2, "left": { "val": 4, "left": null, "right": null }, "right": { "val": 5, "left": null, "right": null } }, "right": { "val": 3, "left": { "val": 6, "left": null, "right": null }, "right": { "val": 7, "left": null, "right": null } } }, "count": 7 }, "2": { "node": { "val": 3, "left": { "val": 6, "left": null, "right": null }, "right": { "val": 7, "left": null, "right": null } }, "count": 3 }, "3": { "node": { "val": 7, "left": null, "right": null }, "count": 1 } }"