某石油公司计划建造一条由东向西的主输油管道。该管道要穿过一个有n口油井的油田，从每口油井都要有一条输油管道沿最短路经(或南或北)与主管道相连。如果给定n口油井的位置,即它们的x坐标（东西向）和y坐标（南北向）,应如何确定主管道的最优位置,即使各油井到主管道之间的输油管道长度总和最小的位置?证明可在线性时间内确定主管道的最优位置-An oil company plans to build a from east to west of the main pipeline. The pipeline to pass through a n wells of oil fields, oil wells from each must have a pipeline along the shortest path (or South or North) connected with the competent Road. N If given the location of oil wells, that is, their x coordinates (east-west) and y coordinates (north-south), should be how to determine the optimal location of the competent Road, even the well-to-charge of Road between the length of the sum of the smallest oil pipeline location? proved to be linear time to determine the optimal position in charge of Road