考虑两个平面图,一个染成红色,另一个染成绿色.两个图同时2-胞腔嵌入平面时,在一定的限制条件下,红色的边与绿色的边会相交.称这样的交点为交叉点.在所有的嵌入方式中交叉点的最小个数称为交叉数.本文利用图的划分和最小边割集,把这种交叉数问题转化为一类整数规划问题,得出了一些结果.
Consider a red planar graph and a green planar graph simutaneously 2-cell embedded on a surface. With some restriction, a red edge can cross a green edge. This paper studied the minimum number of these red-green crosses by using technique of integer programming, and some results are obtained.