Compute exclusive CPU time from nested logs

You are given logs from a single-threaded CPU that runs `n` functions (IDs `0` to `n-1`). Each log entry is a string in the format: - `"functionId:start:timestamp"` or - `"functionId:end:timestamp"` Rules/semantics: - The CPU runs at most one function at a time. - A function can call other functions; calls are properly nested (well-formed like a stack). - `start` means the function begins executing at the **start** of `timestamp`. - `end` means the function finishes executing at the **end** of `timestamp` (inclusive). - Timestamps are non-decreasing across the log list. **Task:** Return an array `ans` of length `n` where `ans[i]` is the **exclusive** time spent executing function `i` (time spent in its own body excluding time spent in functions it calls). **Input:** - Integer `n` - List of strings `logs` **Output:** - Integer array `ans` **Example:** - `n = 2` - `logs = ["0:start:0","1:start:2","1:end:5","0:end:6"]` - Output: `[3,4]` **Constraints (typical interview assumptions):** - `1 <= n <= 10^5` - `1 <= logs.length <= 10^5` - Log format is valid and properly nested.