If you have young kids (6 or 7) who understand multiplication and like math, Gauss's formula is such a magical thing to show them, because it seems like it'd be impossible to shortcut adding up all those numbers that way, on the surface, and it's such an easy thing to prove visually.
Inverting Gauss’ Formula
11–17 of 17 posts
Re: Inverting Gauss’ Formula
#12A while back I interviewed with a networking company in the bay area and one of the things the interviewer asked me do was to devise an algorithm to walk the fully connected graph without visiting any edge twice if possible. Was a nice problem to discuss, he moved me along nicely in my thought process and we eventually reached a recursive solution. So the length of this walk is basically this formula. He told me they…
A fully connected graph with an even number of vertices will have odd degrees for all of them, and so can't have an Eulerian path.
Re: Inverting Gauss’ Formula
#13A while back I interviewed with a networking company in the bay area and one of the things the interviewer asked me do was to devise an algorithm to walk the fully connected graph without visiting any edge twice if possible. Was a nice problem to discuss, he moved me along nicely in my thought process and we eventually reached a recursive solution. So the length of this walk is basically this formula. He told me they…
Isn't the length of the walk the number of edges?
Re: Inverting Gauss’ Formula
#14A while back I interviewed with a networking company in the bay area and one of the things the interviewer asked me do was to devise an algorithm to walk the fully connected graph without visiting any edge twice if possible. Was a nice problem to discuss, he moved me along nicely in my thought process and we eventually reached a recursive solution. So the length of this walk is basically this formula. He told me they…
Re: Inverting Gauss’ Formula
#15A while back I interviewed with a networking company in the bay area and one of the things the interviewer asked me do was to devise an algorithm to walk the fully connected graph without visiting any edge twice if possible. Was a nice problem to discuss, he moved me along nicely in my thought process and we eventually reached a recursive solution. So the length of this walk is basically this formula. He told me they…
I assume that's only possible in the general case for an odd number of vertices? A fully connected graph with an even number of vertices will have odd degrees for all of them, and so can't have an Eulerian path.
Re: Inverting Gauss’ Formula
#16A while back I interviewed with a networking company in the bay area and one of the things the interviewer asked me do was to devise an algorithm to walk the fully connected graph without visiting any edge twice if possible. Was a nice problem to discuss, he moved me along nicely in my thought process and we eventually reached a recursive solution. So the length of this walk is basically this formula. He told me they…
Re: Inverting Gauss’ Formula
#17A while back I interviewed with a networking company in the bay area and one of the things the interviewer asked me do was to devise an algorithm to walk the fully connected graph without visiting any edge twice if possible. Was a nice problem to discuss, he moved me along nicely in my thought process and we eventually reached a recursive solution. So the length of this walk is basically this formula. He told me they…
I assume that's only possible in the general case for an odd number of vertices? A fully connected graph with an even number of vertices will have odd degrees for all of them, and so can't have an Eulerian path.