数据库系统

开发平台：

Unix_Linux

real_city.data：源码内容

							0	Oakland	((-122,37.9),(-121.7,37.9),(-121.7,37.4),(-122,37.4))
Oakland	((-121.7,37.4),(-121.7,37),(-122.1,37),(-122.1,37.3),(-122,37.3),(-122,37.4))
Oakland	((-122.1,37.3),(-122.2,37.5),(-122,37.5))
Berkeley	((-122.3,37.9),(-122,37.9),(-122,37.6),(-122.3,37.6))
Lafayette	((-122.3,37.4),(-122.2,37.4),(-122.2,37),(-122.3,37))

						