问题描述：

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?

编程任务：

给定n 口油井的位置,编程计算各油井到主管道之间的输油管道最小长度总和。-Problem Descr iption: A oil company plans to build a main oil pipeline from east to west. The pipeline must pass through a n wells in oil fields. From each of wells must have an oil pipeline along the Shortest Path (or the South or North) and the director of Road connected. If for a given n the location of wells, that is, their x coordinates (east-west) and y coordinates (north-south), should be how to determine the optimal position in charge of Road, even though the well-to-head Road, the length of the pipeline between the sum of the minimum position? programming tasks: Given the location of wells n, programming calculate their well-to-head Road, the minimum length of the pipeline between the sum of.