Euler solved this problem in 1736. He changed this problem into the first graph theory problem by abstract analyzed method.
欧拉在1736年解决了这个问题，他用抽象分析法将这个问题化为第一个图论问题。
2
A progressive representation model for street networks of vector data was presented based on the theory of plane Euclidean graph and abstract complex cell.
基于平面欧几里得图和抽象胞腔复形理论，提出了街道网矢量数据的渐进式表达模型。
3
Abstract: Based on the construction schedule network planning, this paper puts forward the idea and draw steps of compositive horizontal line graph to construction schedule.