x***u
发帖数: 336 | | x***u
发帖数: 336 | 2 $#%#%....
you put a disk with radius 1/2 on each point. Then any two disks are disjoint,
due to your assumption that the distance is at least 1. If two disks are
tangent to each other, then the distance between them is exactly 1.
Then you imagine how many disks you can pack, as closely as possible, around
one disk -- you can at most 6 of them. (try it with some coins.. )
This observation along with many different variances are called packing
argument. You can find in any discrete geometry book. |
|
