TOPOLOGICAL SORT

1. DFS keeps truck of visiting time and finishing time.
   

   read 23.4: f(v) in decreasing order gives topological sort.
   

2. Single-Source Shortest Path: pp. 514-523 relaxation shortest path
   
3. Read 25.4 Shortest path in DAGS. pp. 536 - 538
   Use topological ordering on edges- Only one pass of Bellman-Ford algorithm is enough.
   
4. Chap. 26.1, 26.2