Last Passenger Within Bus Weight Limit

Medium

You are given a boarding queue table named Queue. Table columns: person_id: unique numeric identifier of a passenger person_name: passenger display name weight: passenger weight in kilograms turn: boarding order position (1 is earliest) Operational rules: Passengers are processed strictly by increasing turn. Only one passenger is processed at each turn. The bus has a hard total weight capacity of 1000 kilograms. Boarding stops as soon as adding the next passenger would exceed capacity. Task: Return the person_name of the final passenger who successfully boards. Output requirements: Return exactly one column in this order: person_name Return exactly one row for the final boardable passenger. Supported submission environments: SQL (SQLite 3.27.2) Pandas (Python)

Example 1

Input

Queue:
| person_id | person_name | weight | turn |
|-----------|-------------|--------|------|
| 5         | Alice       | 250    | 1    |
| 4         | Bob         | 175    | 5    |
| 3         | Alex        | 350    | 2    |
| 6         | John Cena   | 400    | 3    |
| 1         | Winston     | 500    | 6    |
| 2         | Marie       | 200    | 4    |

Output

[
  {"person_name":"John Cena"}
]

Explanation

Boarding by turn gives cumulative weights 250, 600, 1000, then 1200. The turn-3 passenger is the last one within capacity.

Example 2

Input

Queue:
| person_id | person_name | weight | turn |
|-----------|-------------|--------|------|
| 11        | Nora Stone  | 400    | 1    |
| 12        | Ravi Hale   | 200    | 2    |
| 13        | Lea Kim     | 300    | 3    |
| 14        | Omar Diaz   | 100    | 4    |
| 15        | Tara Bloom  | 50     | 5    |

Output

[
  {"person_name":"Omar Diaz"}
]

Explanation

The first four passengers sum to exactly 1000, so turn 4 is still valid. Turn 5 would exceed the cap.

Example 3

Input

Queue:
| person_id | person_name | weight | turn |
|-----------|-------------|--------|------|
| 21        | Mira Cole   | 120    | 1    |
| 22        | Jian Park   | 150    | 2    |
| 23        | Ivan Reed   | 170    | 3    |
| 24        | Zoe Lane    | 190    | 4    |

Output

[
  {"person_name":"Zoe Lane"}
]

Explanation

Total cumulative weight is 630, so everyone boards and the final turn in the queue is the answer.

Constraints

1 <= number of rows in Queue <= 10,000
1 <= person_id <= 1,000,000,000
1 <= weight <= 2,000
turn values are unique and range from 1 to n
person_id values are unique
person_name is a non-empty string
Bus total weight capacity is fixed at 1000
Passengers are processed in ascending turn order
The first passenger is guaranteed to fit within capacity
Return columns exactly as: person_name
For SQL submissions, use SQLite 3.27.2 semantics
For Pandas submissions, return a DataFrame with column: person_name

Queue: | person_id | person_name | weight | turn | |-----------|-------------|--------|------| | 5 | Alice | 250 | 1 | | 4 | Bob | 175 | 5 | | 3 | Alex | 350 | 2 | | 6 | John Cena | 400 | 3 | | 1 | Winston | 500 | 6 | | 2 | Marie | 200 | 4 |

Queue: | person_id | person_name | weight | turn | |-----------|-------------|--------|------| | 11 | Nora Stone | 400 | 1 | | 12 | Ravi Hale | 200 | 2 | | 13 | Lea Kim | 300 | 3 | | 14 | Omar Diaz | 100 | 4 | | 15 | Tara Bloom | 50 | 5 |

Queue: | person_id | person_name | weight | turn | |-----------|-------------|--------|------| | 21 | Mira Cole | 120 | 1 | | 22 | Jian Park | 150 | 2 | | 23 | Ivan Reed | 170 | 3 | | 24 | Zoe Lane | 190 | 4 |