Graphs with negative edge costs, Data Structure & Algorithms

Assignment Help:

We have discussed that the above Dijkstra's single source shortest-path algorithm works for graphs along with non-negative edges (like road networks). Given two scenarios can emerge out of negative cost edges into a graph:

  • Negative edge along non- negative weight cycle reachable from the source.
  • Negative edge along non-negative weight cycle reachable from source.

529_Graphs with Negative Edge costs.png

Figure: A Graph with negative edge & non-negative weight cycle

The net weight of the cycle is 2(non-negative)

437_Graphs with Negative Edge costs1.png

 Figure: A graph with negative edge and negative weight cycle

The net weight of the cycle is 3(negative) (refer to above figure). The shortest path from A to B is not well defined as the shortest path to this vertex are infinite, that means , by traveling each cycle we can reduced the cost of the shortest path by 3, like (S, A, B) is path (S, A, B, A, B) is a path with less cost and so forth.

Dijkstra's Algorithm works only for directed graphs along non-negative weights (cost).


Related Discussions:- Graphs with negative edge costs

Red black tree, red black tree construction for 4,5,6,7,8,9

red black tree construction for 4,5,6,7,8,9

Explain the method of overlapping and intersecting, Overlapping or Interse...

Overlapping or Intersecting A polygon overlaps or intersects the current background if any of its sides cuts the edges of the viewport as depicted at the top right corner of th

Process of channel access, Channel access In first generation systems, ...

Channel access In first generation systems, every cell supports a number of channels. At any given time a channel is allocated to only one user. Second generation systems also

Total impedent of the circuit, an electrical student designed a circuit in...

an electrical student designed a circuit in which the impedence in one part of a series circuit is 2+j8 ohms and the impedent is another part of the circuit is 4-j60 ohm mm program

An undirected graph g with n vertices and e edges, An undirected graph G wi...

An undirected graph G with n vertices and e edges is shown by adjacency list.  What is the time required to generate all the connected components? O (e+n)

Infix expression has balanced parenthesis or not, Q. By making use of stack...

Q. By making use of stacks, write an algorithm to determine whether the infix expression has balanced parenthesis or not.

Linked list implementation of any circular queue, Link list representation ...

Link list representation of a circular queue is more efficient as it employs space more competently, of course with the added cost of storing the pointers. Program 7 gives the link

Last in first out method, This method is the reverse of FIFO and assumes th...

This method is the reverse of FIFO and assumes that each issue of stock is made from latest items received in the enterprises .Thus if the last lot to be received is not sufficient

Determine about the post conditions assertion, Determine about the Post con...

Determine about the Post conditions assertion A  post condition is an assertion which should be true at completion of an operation. For instance, a post condition of the squ

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd