The document describes the steps of performing a breadth-first search (BFS) on a graph starting from node A. It shows how BFS enqueues nodes onto a FIFO queue as they are discovered and dequeues them to visit their neighbors, marking nodes as discovered along the way. The BFS finishes after all nodes reachable from A have been visited.

1. Breadth First Search A B F I E H D C G FIFO Queue - front

2. Breadth First Search A B F I E H D C G A FIFO Queue - front enqueue source node

3. Breadth First Search A B F I E H D C G A FIFO Queue - front dequeue next vertex

4. Breadth First Search front visit neighbors of A A B F I E H D C G - FIFO Queue

5. Breadth First Search front visit neighbors of A A B F I E H D C G - FIFO Queue

6. Breadth First Search B front B discovered A B F I E H D C G - A FIFO Queue

7. Breadth First Search B front visit neighbors of A A F I E H D C G - B A FIFO Queue

8. Breadth First Search B I front I discovered A F I E H D C G - B A A FIFO Queue

9. Breadth First Search B I front finished with A A F I E H D C G - B A A FIFO Queue

10. Breadth First Search B I front F I E H D C G - B A A dequeue next vertex FIFO Queue A

11. Breadth First Search I front F I E H D C G - B A A visit neighbors of B FIFO Queue A

12. Breadth First Search I front F I E H D C G - B A A visit neighbors of B FIFO Queue A

13. Breadth First Search I F front F I E H D C G - B A A F discovered B FIFO Queue A

14. Breadth First Search I F front F I E H D C G - B A A visit neighbors of B B FIFO Queue A

15. Breadth First Search I F front F I E H D C G - B A A A already discovered B FIFO Queue A

16. Breadth First Search I F front F I E H D C G - B A A finished with B B FIFO Queue A

17. Breadth First Search I F front F I E H D C G - A A dequeue next vertex B FIFO Queue B A

18. Breadth First Search F front F I E H D C G - A A visit neighbors of I B FIFO Queue B A

19. Breadth First Search F front F I E H D C G - A A visit neighbors of I B FIFO Queue B A

20. Breadth First Search F front F I E H D C G - A A A already discovered B FIFO Queue B A

21. Breadth First Search F front F I E H D C G - A A visit neighbors of I B FIFO Queue B A

22. Breadth First Search F E front F I E H D C G - A A E discovered B I FIFO Queue B A

23. Breadth First Search F E front F I E H D C G - A A visit neighbors of I B I FIFO Queue B A

24. Breadth First Search F E front F I E H D C G - A A F already discovered B I FIFO Queue B A

25. Breadth First Search F E front F I E H D C G - A A I finished B I FIFO Queue B A

26. Breadth First Search F E front F E H D C G - A A dequeue next vertex B I FIFO Queue B A I

27. Breadth First Search E front F E H D C G - A A visit neighbors of F B I FIFO Queue B A I

28. Breadth First Search E G front F E H D C G - A A G discovered B I F FIFO Queue B A I

29. Breadth First Search E G front F E H D C G - A A F finished B I F FIFO Queue B A I

30. Breadth First Search E G front E H D C G - A A dequeue next vertex B I F FIFO Queue I F B A

31. Breadth First Search G front E H D C G - A A visit neighbors of E B I F FIFO Queue I F B A

32. Breadth First Search G front H D C G - A A E finished B I F FIFO Queue I F B A E

33. Breadth First Search G front H D C G - A A dequeue next vertex B I F FIFO Queue I F B A E

34. Breadth First Search front H D C G - A A visit neighbors of G B I F FIFO Queue I F B A E

35. Breadth First Search C front H D C G - A A C discovered B I F G FIFO Queue I F B A E

36. Breadth First Search C front H D C G - A A visit neighbors of G B I F G FIFO Queue I F B A E

37. Breadth First Search C H front H D C G - A A H discovered B I F G G FIFO Queue I F B A E

38. Breadth First Search C H front H D C G - A A G finished B I F G G FIFO Queue I F B A E

39. Breadth First Search C H front H D C - A A dequeue next vertex B I F G G FIFO Queue I F B A E G

40. Breadth First Search H front H D C - A A visit neighbors of C B I F G G FIFO Queue I F B A E G

41. Breadth First Search H D front H D C - A A D discovered B I F G G C FIFO Queue I F B A E G

42. Breadth First Search H D front H D C - A A C finished B I F G G C FIFO Queue I F B A E G

43. Breadth First Search H D front H D - A A get next vertex B I F G G C FIFO Queue I F B A E G C

44. Breadth First Search D front H D - A A visit neighbors of H B I F G G C FIFO Queue I F B A E G C

45. Breadth First Search D front D - A A finished H B I F G G C FIFO Queue I F B A E G H C

46. Breadth First Search D front D - A A dequeue next vertex B I F G G C FIFO Queue I F B A E G H C

47. Breadth First Search front D - A A visit neighbors of D B I F G G C FIFO Queue I F B A E G H C

48. Breadth First Search front - A A D finished B I F G G C FIFO Queue I F B A E G H C D

49. Breadth First Search front - A A dequeue next vertex B I F G G C FIFO Queue I F B A E G H C D

50. Breadth First Search front STOP E H D - A A B I F G G C FIFO Queue I F B A G C