Compute meeting rooms and evaluate RPN

You are given two independent coding tasks. ## Task 1: Minimum number of meeting rooms Given a list of meeting time intervals `intervals`, where each interval is `[start, end)` with integer times and `start < end`, compute the minimum number of conference rooms required so that no meetings assigned to the same room overlap. - Two meetings do **not** overlap if one ends at the exact time the other starts (because intervals are half-open `[start, end)`). **Input:** `intervals: List[List[int]]` **Output:** `int` (minimum number of rooms) **Constraints (typical):** - `0 <= intervals.length <= 10^5` - `0 <= start < end <= 10^9` ## Task 2: Evaluate an expression in Reverse Polish Notation Given an array of strings `tokens` representing an arithmetic expression in Reverse Polish Notation (postfix form), evaluate the expression and return the result as an integer. - Valid operators are `"+"`, `"-"`, `"*"`, `"/"`. - Each operand is an integer string (may be negative). - Division should truncate toward zero. - The input expression is guaranteed to be valid. **Input:** `tokens: List[str]` **Output:** `int` **Constraints (typical):** - `1 <= tokens.length <= 10^4` - Operands fit in 32-bit signed integer range; intermediate results fit in 32-bit signed integer range.