Map-four-staining

代码说明：

  用不多于四种颜色为地图染色，使相邻的行政区不重色，是计算机科学中著名的“四染色”的典型应用，应用这个思想，是以回溯的算法对一幅给定的地图染色。是对数据结构中栈的应用。(With no more than four colors map staining the adjacent borough is not heavy color, typical applications of computer science "stain" the application of this idea, a backtracking algorithm on a given mapstaining. The application of the stack data structure.)