在一个按照东西和南北方向划分成规整街区的城市里，n个居民点散乱地分布在不同的街区中。用x坐标表示东西向，用y表示南北向。各居民点的位置可以由坐标（x，y）表示。街区中任意两点（x1，y1）和（x2，y2）之间的距离可以用数值|x1-x2|+|y1-y2|度量。-In a north-south direction in accordance with things and is divided into regular city blocks, n a settlements scattered distributed in different neighborhoods. East-west coordinates with x, y said with a north-south. The location of the settlements can be coordinates (x, y) said. Blocks in any two points (x1, y1) and (x2, y2) can use the distance between the values | x1-x2 |+ | y1-y2 | metrics.