A Systematic Rotation Method to Color the Historic Heawood Map by Four Colors
A Systematic Rotation Method to Color the Historic Heawood Map by Four Colors
复制标题
一种用四种颜色对希伍德历史地图进行着色的系统旋转方法
DOI:
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发表时间:
2022
期刊:
影响因子:
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通讯作者:
Weiguo Xie
中科院分区:
文献类型:
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作者:
Weiguo Xie
The four-color problem was first posed by Francis Guthrie in 1852. Over a century, many researchers tried many ways and obtained some useful results. One proposed proof was given by Alfred Kempe using Kempe Chain in 1879, but Percy Heawood found counterexample of Kempe’s proof in 1890 [3]. This historic Heawood map has 25 regions. It can be very challenging to just use trial and error method to make it four-colored. In this paper, a systematic way to color the map with four colors using a novel method of rotation [4] inspired by a rotation principle from Zhuan Falun book [2] of Falun Dafa will be demonstrated. It shows that the novel method of rotation is very powerful and can provide a systematic approach to make maps four-colored.