Algorithm

Imagine each room in a house is connected by doors to its adjacent rooms (left child, right child, and the one you came from is parent). If a fire starts in one room, it spreads to all connected rooms every second. So, we convert this structure into a network (graph), where each room (node) knows which other rooms it connects to. Then, we perform a level-order BFS starting from the burning room and count how many seconds it takes until every room is on fire.

Convert Binary Tree to Graph: Use DFS or BFS to traverse the tree. For each node:
- Create a bi-directional edge between the node and its left child (if exists).
- Create a bi-directional edge between the node and its right child (if exists).
Store these edges in an adjacency list format.
Initialize BFS: Create a queue and a visited set.
- Push the target node’s value into the queue.
- Mark it as visited.
- Initialize a time counter to 0.
Perform BFS Level-by-Level: While the queue is not empty:
- Get the current level size (number of nodes burning at this second).
- For each node at this level:
  - Explore all its neighbors (from the graph).
  - If a neighbor is not visited:
    - Mark it visited and add it to the queue.
- Increment the time counter after each level.
Return time Once all nodes are burned( when queue gets empty).