Minimize Two-Person Boats under a Weight Limit

### Problem Every person in `people` must board a boat. Each boat carries at most two people, and their combined weight cannot exceed `limit`. There is no limit on available boats. Return the fewest boats required. ```cpp class Solution { public: int numRescueBoats(vector<int>& people, int limit); }; ``` ### Examples **Example 1:** ```text Input: people = [2,3,3,4], limit = 5 Output: 3 Explanation: Use boats(2,3),(3),(4). Weight4 cannot share with anyone, and the other three need at least two boats. ``` **Example 2:** ```text Input: people = [1,1,2,2], limit = 3 Output: 2 Explanation: Pair each weight1 person with a weight2 person; two boats also meet the two-person lower bound. ``` ### Constraints - `1 <= people.length <= 5*10^4`. - `1 <= people[i] <= limit <= 3*10^4`. ### Contract considerations The output is the minimum count; passenger assignments are not returned. ```hint Read the boundary condition Before choosing a partner, ask whether the heaviest can share even with the lightest. ``` ### Boundary reminders The output is the minimum count; passenger assignments are not returned.