Grid Representation

• Each string represents one row of the grid.
• Values within a row are separated by commas.
• -1 represents a wall or obstacle.
• 0 represents a gate.
• 2147483647 represents an empty room.

Distance Rules

• Movement is allowed one cell up, down, left, or right.
• Walls cannot be crossed.
• Each reachable empty room is assigned to a gate having the minimum distance from it.
• If multiple gates are equally near, assign the room to the gate with the smaller row index.
• If the row indices are also equal, assign it to the gate with the smaller column index.
• An empty room that cannot reach any gate is not assigned to a gate.
• Gate cells themselves are not counted as assigned rooms.

Result Rules

• Return every gate assigned to the maximum number of empty rooms.
• Gates with no assigned rooms are still considered. If no empty room is assigned to any gate, return every gate because all gates are tied with zero assigned rooms.
• Represent each gate as "row,column", using zero-based indices.
• Return the gates in ascending row order and then ascending column order.
• If the grid contains no gates, return an empty list.

Method

Find Most Common Gates

List<String> findMostCommonGates(List<String> grid)

Constraints

• 1 ≤ grid.size() ≤ 500
• 1 ≤ number of values in each row ≤ 500
• Every row contains the same number of values.
• Each value is -1, 0, or 2,147,483,647.
• Values in each row are separated by commas without spaces.

Examples

Example 1

Example 2

Example 3