ASAP PLS In each part, either draw a graph with the given specifications or explain why no such graph exists. (a). A connected graph with four vertices that has Euler circuit(s) but not a Hamiltonian...

ASAP PLS

In each part, either draw a graph with the given specifications or explain why no such graph exists.

(a). A connected graph with four vertices that has Euler circuit(s) but not a Hamiltonian circuit.

(b). A connected graph with five vertices that has Hamiltonian circuits but not a Euler circuit.

(c). A digraph with indegree 5 and outdegree 6.

(d). A binary tree to represent expression (? ⁄ ? − ?) + ? ∙ (? + (? − ? ÷ h)).