How do I implement A* search in Swift?

The A* search algorithm is an informed search algorithm that is used for pathfinding and graph traversal. It efficiently finds the shortest path from a start node to a goal node using a heuristic to guide its search.

In Swift, you can implement the A* search algorithm by utilizing data structures such as priority queues to manage nodes, and NSData or dictionaries to maintain the costs of traversing each path.

Example Implementation of A* Search in Swift


        // A* search algorithm implementation in Swift
        class Node {
            var name: String
            var neighbors: [Node]
            var heuristicCost: Double
            
            init(name: String, heuristicCost: Double) {
                self.name = name
                self.neighbors = []
                self.heuristicCost = heuristicCost
            }
        }
        
        func aStarSearch(start: Node, goal: Node) -> [Node]? {
            var openSet: Set = [start]
            var cameFrom: [Node: Node] = [:]
            
            var gScore: [Node: Double] = [start: 0]
            var fScore: [Node: Double] = [start: start.heuristicCost]
            
            while !openSet.isEmpty {
                let current = openSet.min { fScore[$0, default: Double.infinity] < fScore[$1, default: Double.infinity] }!
                
                if current === goal {
                    var path: [Node] = []
                    var currentNode: Node? = current
                    
                    while currentNode != nil {
                        path.append(currentNode!)
                        currentNode = cameFrom[currentNode!]
                    }
                    
                    return path.reversed()
                }
                
                openSet.remove(current)
                
                for neighbor in current.neighbors {
                    let tentativeGScore = gScore[current, default: Double.infinity] + 1 // Assuming the cost to move to neighbor is 1
                    if tentativeGScore < gScore[neighbor, default: Double.infinity] {
                        cameFrom[neighbor] = current
                        gScore[neighbor] = tentativeGScore
                        fScore[neighbor] = tentativeGScore + neighbor.heuristicCost
                        openSet.insert(neighbor)
                    }
                }
            }
            return nil // Path not found
        }

How do I implement A* search in Swift?

Example Implementation of A* Search in Swift

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How do I implement A* search in Swift?

Example Implementation of A* Search in Swift

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