Maximum Riders

Problem Statement

Maximum Riders Problem Description Uber operates a premium airport service that transports riders to and from the airport. The car can carry any number of riders at once. On each round trip, the driver starts from the Uber hub at (0, 0) , drives to the airport at (n-1, n-1) , and then returns to the hub, picking up riders along the way. The city map is an n x n grid city , where: 0 is an empty road cell (valid for travel), 1 is a road cell with one rider waiting to be picked up, -1 is a blocked road (an obstruction that cannot be entered). Movement Rules The driver always starts at the hub (0, 0) . To reach the airport (n-1, n-1) , the driver can only move right or down , one cell at a time, along valid roads. On the return trip back to the hub, the driver can only move left or up , one cell at a time, 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 ). A rider is therefore collected at mo