Using a De Bruijn graph, find a linear string of minimal length that contains every

DNA $2-$mer exactly once $[\text{'}$AA$\text{'},\text{'}$AC$\text{'},\text{'}$AT$\text{'},\text{'}$AG$\text{'},\text{'}$CA$\text{'},\text{'}$CC$\text{'},\text{'}$CT$\text{'},\text{'}$CG$\text{'},\text{'}$TA$\text{'},\text{'}$TC$\text{'},\text{'}$TT$\text{'},\text{'}$TG$\text{'},$

$\text{'}$GA$\text{'},\text{'}$GC$\text{'},\text{'}$GT$\text{'},\text{'}$GG$\text{'}].$ A DNA $2-$mer consists of two characters from the set $[\text{'}$A$\text{'},\text{'}$C$\text{'},\text{'}$T$\text{'},$

$\text{'}$G$\text{'}]$ and represents overlapping pairs in DNA sequences. If you choose to solve with a

coding approach, your code should take a list of DNA $2-$mers as input and should give

an output of the resulting linear string.

Note: Programming or a manual hand solution is acceptable forthis problem.

B$.$ What is the k value if we would like to have a De Bruijn graph having only two nodes

to represent the string from Part A$?$ Show your graph.