A O(E) Time Shortest Path Algorithm For Non Negative Weighted Undirected Graphs
نویسندگان
چکیده
In most of the shortest path problems like vehicle routing problems and network routing problems, we only need an efficient path between two points—source and destination, and it is not necessary to calculate the shortest path from source to all other nodes. This paper concentrates on this very idea and presents an algorithms for calculating shortest path for (i) nonnegative weighted undirected graphs (ii) unweighted undirected graphs. The algorithm completes its execution in O(|E|) for all graphs except few in which longer path (in terms of number of edges) from source to some node makes it best selection for that node. The main advantage of the algorithms is its simplicity and it does not need complex data structures for implementations. Keywords-component; Shortest Path, Directed Graphs, Undirected Graphs, Algorithm, Theoretical Computer Science
منابع مشابه
A Shortest Path Algorithm for Real-Weighted Undirected Graphs
We present a new scheme for computing shortest paths on real-weighted undirected graphs in the fundamental comparison-addition model. In an efficient preprocessing phase our algorithm creates a linear-size structure that facilitates single-source shortest path computations in O(m logα) time, where α = α(m,n) is the very slowly growing inverse-Ackermann function, m the number of edges, and n the...
متن کاملShortest paths in conservative graphs
We give a polynomial algorithm to compute shortest paths in weighted undirected graphs with no negative cycles (conservative graphs). We show that our procedure gives a simple algorithm to compute optimal T-joins (and consequently all of their special cases, including weighted matchings). We nally give a direct algorithmic proof for arbitrary weights of a theorem of Seb} o characterizing conser...
متن کاملNew Parameterized Algorithms for APSP in Directed Graphs
All Pairs Shortest Path (APSP) is a classic problem in graph theory. While for general weighted graphs there is no algorithm that computes APSP in O(n3−ε) time (ε > 0), by using fast matrix multiplication algorithms, we can compute APSP in O(n logn) time (ω < 2.373) for undirected unweighted graphs, and in O(n2.5302) time for directed unweighted graphs. In the current state of matters, there is...
متن کاملMultiple-Source Shortest Paths in Embedded Graphs
Let G be a directed graph with n vertices and non-negative weights in its directed edges, embedded on a surface of genus g, and let f be an arbitrary face of G. We describe a randomized algorithm to preprocess the graph in O(gn log n) time with high probability, so that the shortest-path distance from any vertex on the boundary of f to any other vertex in G can be retrieved in O(log n) time. Ou...
متن کاملA new approach to all-pairs shortest paths on real-weighted graphs
We present a new all-pairs shortest path algorithm that works with real-weighted graphs in the traditional comparison-addition model. It runs in O(mn+n2 log log n) time, improving on the long-standing bound of O(mn + n2 logn) derived from an implementation of Dijkstra's algorithm with Fibonacci heaps. Here m and n are the number of edges and vertices, respectively. Our algorithm is rooted in th...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- CoRR
دوره abs/0911.0174 شماره
صفحات -
تاریخ انتشار 2009