Can you visit all rooms and score parentheses?

## Problem 1: Visit all locked rooms with keys There are **n** rooms labeled **0..n-1**. All rooms are locked except room **0**. - When you enter room **i**, you find a set of keys `rooms[i]`. - Each key is an integer `k` that unlocks room `k`. - You may collect and carry all keys you find. **Task:** Given `rooms: List[List[int]]`, return `true` if you can eventually visit **every** room starting from room `0`, otherwise return `false`. **Input/Output** - Input: `rooms`, where `rooms[i]` is the list of keys in room `i` - Output: boolean **Constraints (typical):** - `1 <= n <= 10^4` - `0 <= rooms[i].length <= 10^4` - Keys are in range `0..n-1` (may include duplicates) --- ## Problem 2: Compute the score of a balanced parentheses string You are given a **balanced** parentheses string `s` consisting only of `'('` and `')'`. Define the score recursively: 1. `"()"` has score `1` 2. Concatenation: if `A` and `B` are balanced, then `score(A + B) = score(A) + score(B)` 3. Nesting: if `A` is balanced, then `score("(" + A + ")") = 2 * score(A)` **Task:** Return `score(s)`. **Input/Output** - Input: balanced string `s` - Output: integer score **Constraints (typical):** - `1 <= s.length <= 10^5` - `s` is guaranteed balanced