2021-021

In a graph, a "tree edge" is an edge that is present in the tree obtained after performing DFS on the graph. Suppose that \(k\) tree edges resulted from a depth-first traversal of an \(n\)-vertex, undirected graph. The number of the connected components in the graph can be calculated as:

1. \( k-1 \)
2. \( k \)
3. \( n-k \)
4. \( n-k+1 \)
5. None of the above

Original idea by: Soroor Salavati