$24\mathrm{.}1-1$

Run the Bellman$-$Ford algorithm on the directed graph of Figure $24\mathrm{.}4,$ using vertex z as the source. In each pass, relax edges in the same order as in the figure, and

show the d and pi values after each pass. Now, change the weight of edge$($z$,$x$)$ to $4$ and run the algorithm again, using s as the source.