Code in C++ Hrelated to data structured

A tree Not a tres Not a tree Not a tres A. We can think of a tree as being a special kind of directed graph. To model a tree as a graph, we make the nodes of the tree become nodes in the graph, and draw an edge from a parent node to each of its children. The drawing on the left shows a tree as a graph; the other three directed graphs do not correspond to a tree. Suppose we want to check if a given directed graph corresponds to a tree. What properties should we check that the graph has? Write down a list of properties such that, if a directed graph has those properties, it must be a tree. You can refer to standard properties of graphs in your answer without explaining them