Solve maze reachability and two follow-ups

You are given three independent coding tasks.

1) Maze reachability with “rolling ball” movement

Given an m x n grid maze where 0 means empty and 1 means wall, a ball starts at start = (sr, sc) and wants to reach destination = (dr, dc).

Movement rule: from any cell, you may choose one of 4 directions (up/down/left/right). The ball then rolls in that direction until the next step would hit a wall or go out of bounds; it stops at the last valid empty cell before the obstacle. You may then choose a new direction.

Return whether the ball can stop exactly at destination.

Input: maze: int[m][n], start: int[2], destination: int[2]

Output: bool

Constraints (typical): 1 ≤ m,n ≤ 100, maze[i][j] ∈ {0,1}, start/destination are empty.

2) Compute the diameter of a binary tree

Given the root of a binary tree, compute its diameter, defined as the maximum number of edges on any path between two nodes in the tree.

Input: root (binary tree)

Output: int

3) Exclusive time of functions from logs

There are n single-threaded functions labeled 0..n-1. You are given a list of logs in chronological order.

Each log is a string in the format:

• "id:start:timestamp" or
• "id:end:timestamp"

Rules:

• A function can call other functions; the CPU executes only the top of the call stack.
• end:timestamp is inclusive (i.e., the function runs through that timestamp).

Return an array ans where ans[i] is the exclusive time spent in function i.

Input: n: int, logs: string[]

Output: int[]

Constraints (typical): 1 ≤ n ≤ 100, 1 ≤ logs.length ≤ 10^4, timestamps are non-decreasing integers.