Company: uber_3sep
Difficulty: medium
Maximum Riders Problem Description Uber operates a premium airport service that transports riders to and from the airport. The car can carry multiple riders at once. On each round trip, the driver starts from the Uber hub (0,0) , drives to the airport (n-1, n-1) , and then returns back to the hub, potentially picking up more riders along the way. The city map is represented as an n x n grid, where: 0 → an empty road cell (valid for travel). 1 → a road cell with a rider waiting to be picked up. -1 → a blocked road (obstruction, not passable). Movement Rules: The Uber driver always starts at the hub (0,0) . To reach the airport (n-1, n-1) , the driver can only move right (→) or down (↓) along valid roads. On the return trip back to the hub, the driver can only move left (←) or up (↑) along valid roads. If the driver passes through a road cell with a rider ( 1 ), that rider is picked up immediately, and the cell becomes empty ( 0 ). If there is no valid