Solution: Breadth First Graph Traversal

Solution #1: Iterative

In this algorithm, we begin from a selected node (it can be a root node) and traverse the graph layerwise (one level at a time). All neighbor nodes (those connected to the source node) are explored, then we move to the next level of neighbor nodes.

Simply, as the name Breadth First suggests, we traverse the graph by first moving horizontally and visiting all the nodes of the current layer, then moving to the next layer.