# Questions tagged [shortest-path]

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1answer
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### Number of simple paths between two vertices in a DAG

Let $G = (N, A)$ be a connected acyclic digraph (DAG). Furthermore, let $s \in N$ and $t \in N$ be two vertices on this graph, such that $t$ is reachable from $s$. My problem is: how many simple $s-t$...
2answers
71 views

### Bellman-Ford with Non-edge-decomposable Path Weights

Consider a directed graph $G(V,E)$ with non-negative edge weights. Also, let us define the weight of a path as non-edge-decomposable, that is, the weight of a path cannot be written as the sum of a ...
1answer
107 views

### When is extra vertex required in arbitrage detection using Bellman Ford?

I am studying applications of shortest path, in particular arbitrage. Specifically, I was reading these two resources: https://stackoverflow.com/questions/2282427/interesting-problem-currency-...
1answer
110 views

### Finding Cheapest n-Path [closed]

Given a weighted directed acyclic graph, how can I find the cheapest path from an Origin Vertex to a Destination Vertex which ...
1answer
127 views

### Finding shortest path while maximizing the number of overlapping edges

The shortest path problem between 2 arbitrary nodes is one that has been covered extensively and the solution is well-known. Consider the edge costs to be arbitrary. Consider the following variant: ...
1answer
250 views

### What exactly is Lawler's modification to Yen's algorithm and how does it work?

I recently read about Yen's algorithm, I understand the algorithm and it seems correct, however Wikipedia mentions that there exists "Lawler's modification" to the algorithm, which is described as ...
1answer
425 views

### Minimum Union-Sum Cost Path

I have a minimum cost path selection problem that is different from the usual shortest path in that each type of cost is accounted only once in the total cost of the path if multiple edges on the path ...
1answer
421 views

### Maximum difference between two shortest paths

My problem is the following maximization problem: Given: A graph $G=(V,E)$, lower bounds $l \in \{0,1,..,K\}^E$ and upper bound $u \in \{0,1,..,K\}^E$ for the edge weights, a source $s$ and two ...
2answers
3k views

1answer
145 views

### Anyone recognize this as a special type of multi-commodity flow problem?

Consider this problem:  \begin{align} \min_{y,z,l \geq 0} \quad & g(y,z,l) := \sum_{(i,j)\in E} \sum_p (-w_{ijp}) y_{ijp} & \\ \textrm{s.t.} \quad & \left( \sum_{(i,j)\in E} y_{ijp} + ...
3answers
733 views

### Shortest distance problem with length as functions of time

Motivation The other day, I was travelling around the city with public transport and I made up an interesting graph problem modelling the problem of finding the shortest-time connection between two ...
1answer
239 views

### What is the proof that visibility graphs can be used to compute the shortest path?

I am trying to understand what the proof is that constructing a visibility graph and searching on can give you the shortest path between two points, avoiding a set of convex polygons. I am trying ...
1answer
165 views

### Are there any heuristics that works solely on graphs?

I'm exploring heuristics in A* and apparently all heuristics require coordinates of all the locations to calculate a h-cost. This is fine if you are working on grids, but what if you need to work ...
0answers
475 views

### Path finding on graph with state dependent edge costs

I'm looking for a version of path planning that is able to find paths in a graph where edge costs depend on the state of the moving entity. In such cases, it is required to also consider trade-offs, i....
1answer
74 views

### Constant Width Max Sum Product Multi-objective Shortest path problem

This question is a follow-up on the question I asked three days ago here. For convenience I restate it here. I am given a graph. Each edge is labelled by a vector of numbers, called weights. They ...
1answer
154 views

### Max Sum Product Multi-objective Shortest path problem

Is anything known about the following problem: I am given a graph. Each edge is labelled by a vector of numbers, called weights. They are numbers between 0 and 1. A path is first assigned a vector, ...
1answer
82 views

### Cooperative Pathfinding to minimize global costs

There are some algorithms and methods around, that allow cooperative pathfinding. Unfortunately they all seem to aim at avoiding collisions or conflicts between entities. I'm looking for an algorithm ...
0answers
513 views

### Shortest non-crossing geometric paths

I have a plane graph $G$ and a set of $k$ vertex pairs $\{s_1,t_1\}, \dots, \{s_k, t_k\}$. The goal is to find $k$ non-crossing paths connecting the pairs of terminals $s_i$ with $t_i$ in the graph so ...
1answer
160 views

2answers
373 views

### Why is label pruning possible with hub labeling?

Hub labeling (HL) computes superlabels using the vertices visited by the forward and reverse Contraction Hierarchies (CH) search. Those labels are then pruned (see HL, sec. 4.2) to generate strict ...
0answers
134 views

### Distance oracles in trees

Given an unweighted tree $T=(V,E)$ what is the minimum number of distance oracles that allow to detect the position in the graph of every node $v$? A distance oracle is "special node" $u$ of the ...
1answer
2k views

### Run Dijkstra's algorithm twice to detect negative-weight cycles?

Dijkstra's algo (for finding single-source shortest path) assumes that once a vertex has been chosen for expansion (aka exploration), its shortest path has been found. This can only be true if there ...
2answers
251 views

### Shortest distance/path between two households

If you wanted to know the shortest distance/path between two household addresses, which data structure(s) would you use to return the answer efficiently? Say you are considering the set of all ...
1answer
254 views

1answer
496 views

### Breadth first search and Eppstein K shortest paths algorithm

I'm trying to understand the algorithm for finding K shortest paths in a graph described by Eppstein in this paper: http://www.ics.uci.edu/~eppstein/pubs/Epp-SJC-98.pdf I have trouble particularly ...
1answer
325 views

### Dynamic all-pairs shortest paths - O(1) query

I'm trying to come up with an algorithm to solve all-pairs shortest paths (APSP) problem in dynamic directed planar graph with nonnegative real weights. Additionally: My primary focus is to achieve ...
0answers
109 views

### What are the differences between Theta* and Field D*?

Both Theta* and Field D* are variations on the A* algorithm, but are adapted for any-angle pathfinding rather than pathfinding constrained to a grid. The primary difference between these two ...