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

Computational complexity, Generally, Computational complexity of algorithms...

Generally, Computational complexity of algorithms are referred to through space complexity (space needed for running program) and time complexity (time needed for running the progr

Explain principle of optimality, Explain principle of Optimality It ind...

Explain principle of Optimality It indicates that an optimal solution to any instance of an optimization problem is composed of  optimal solutions to its subinstances.

Data searching, In file access: what is the difference between serial, seq...

In file access: what is the difference between serial, sequential and indexed sequential searching

If else, design algorithm and flow chart that computes the absolute differe...

design algorithm and flow chart that computes the absolute difference of two values x and y

Write an algorithm outputs number of books using psuedocode, A shop sells b...

A shop sells books, maps and magazines. Every item is identified by a unique 4 - digit code. All books have a code starting with a 1, all maps have a code which starts with a 2 and

Binary tree and binarytree parts, Q. What do you understand by the term Bin...

Q. What do you understand by the term Binary Tree? What is the maximum number of nodes which are possible in a Binary Tree of depth d. Explain the terms given below with respect to

Estimate cost of an optimal diapath, Normally a potential y satisfies y r ...

Normally a potential y satisfies y r = 0 and 0 ³ y w - c vw -y v . Given an integer K³0, define a K-potential to be an array y that satisfies yr = 0 and K ³ y w - c vw -y v

Sparse matrix, How sparse matrix stored in the memory of a computer?

How sparse matrix stored in the memory of a computer?

Sequential files, Data records are stored in some particular sequence e.g.,...

Data records are stored in some particular sequence e.g., order of arrival value of key field etc. Records of sequential file cannot be randomly accessed i.e., to access the n th

Explain binary search tree, Binary search tree. A binary search tree is...

Binary search tree. A binary search tree is a binary tree that is either empty or in which every node having a key that satisfies the following conditions: - All keys (if an

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