American fighters F-16 due to strategic needs, gallow, the distance between the global flight is S, the maximum amount of oil supplied by F-16 is known to allow its maximum continuous navigation distance 1/2 * S (a full box oil fly half of the earth ), All aircraft can only take off from one airport / landing (no airport in the middle), only the plane is allowed to come to the fuel, then, ask a plane to meet the purpose of global flight, at least how many planes do you want to dispatch? (Note: The frame refers to a plane takes off a time)
Here is a discussion of its logic algorithm:
Analysis is available. The distance of the aircraft flying 1 / .2s is full of oil T. The distance of flying 1/4s requires 1 / 2T oil. The distance of 1/8 is flying to 1/4T oil. Set the task machine to: a; escaping machine B! ... BN; divide the earth averaged 8th. Each weight is 1 / 8S.. The fuel tank capacity is: t.
Since the two directions:
First, if escort the aircraft, escort from two two directions (escort the aircraft can take off the task a).
1. Task machine A, escaping machine B1 .... Bn simultaneously takes off from the airport, flying in the same direction. When they are flying to 1/8s. They are all oyster sauces 1 / 4t. At this time, there is a batch of returned escort aircraft B! ..... BJ. (Successfully need 1 / 4T oil), they will continue the remaining T-1 / 4T-1 / 4T = 1 / 2T oil Air escort plane and task a .. Roide the aircraft to return, task A., escaping machine BJ .... BN continues to fly in front of the forward.
2.
