DiscreteMth

可能有種方法for ascending order﹐不過我唔識bor
Form the sequence in descending order
(6,4,4,3,3,2)
Step 1 : Delete the first term 6
Step2 : Substract 1 from each of the next 6 terms
However, since there are only 5 terms inthe sequence (4,4,3,3,2) , the prodecure can not be done. We conclude that there does not exist a simple graph G=(V,E) with degree sequences as follows: (2,3,3,4,4,6)

Or you can say that since there are only 6 vertex, so it is impossible to make a graph such that one vertex has 6 degrees