平面上给定n个点,其两两之间的距离必定存在最大的与最小的。这两个距离在处理数字竞赛中一类有距离限制的组合几何问题时具有独特的作用。本文旨在介绍处理这类问题所涉及的基本知识和解题思路的分析,寻求解题技巧。我们叫平面上给定的n个点的全体为平面点集,记作G。任两点间的最大距离为G的直径,记为d。对于平面点集G,显然有如下事实: 如G的直径是d,则存在A∈G,B∈G, Given n points in the plane, the distance between the two must be the largest and the smallest. These two distances have a unique role in dealing with distance-limited combinatorial geometric problems in digital contests. This article aims to introduce the analysis of basic knowledge and problem-solving ideas involved in dealing with such problems and seek solutions to problems. We call the entirety of the n points given on the plane a set of plane points, denoted as G. The maximum distance between any two points is the diameter of G, denoted as d. For the plane point set G, there are obviously the following facts: If the diameter of G is d, then there are A∈G, B∈G,