Create Diljstra.go

Author: Abhinav kumar

Graphs/Diljstra.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+    "fmt"
+    "math"
+)
+
+// Define a struct to represent a graph.
+type Graph struct {
+    nodes map[string]map[string]float64
+}
+
+// Add an edge to the graph.
+func (g *Graph) AddEdge(node1, node2 string, weight float64) {
+    if g.nodes == nil {
+        g.nodes = make(map[string]map[string]float64)
+    }
+    if g.nodes[node1] == nil {
+        g.nodes[node1] = make(map[string]float64)
+    }
+    if g.nodes[node2] == nil {
+        g.nodes[node2] = make(map[string]float64)
+    }
+    g.nodes[node1][node2] = weight
+    g.nodes[node2][node1] = weight // Assuming an undirected graph
+}
+
+// Dijkstra's algorithm to find the shortest path.
+func Dijkstra(graph Graph, startNode string) map[string]float64 {
+    distances := make(map[string]float64)
+    visited := make(map[string]bool)
+
+    for node := range graph.nodes {
+        distances[node] = math.Inf(1)
+    }
+
+    distances[startNode] = 0
+
+    for {
+        var closestNode string
+        var shortestDistance float64 = math.Inf(1)
+
+        for node, distance := range distances {
+            if !visited[node] && distance < shortestDistance {
+                closestNode = node
+                shortestDistance = distance
+            }
+        }
+
+        if closestNode == "" {
+            break
+        }
+
+        visited[closestNode] = true
+
+        for neighbor, weight := range graph.nodes[closestNode] {
+            if newDistance := distances[closestNode] + weight; newDistance < distances[neighbor] {
+                distances[neighbor] = newDistance
+            }
+        }
+    }
+
+    return distances
+}
+
+func main() {
+    // Create a graph.
+    g := Graph{}
+    g.AddEdge("A", "B", 1)
+    g.AddEdge("A", "C", 4)
+    g.AddEdge("B", "C", 2)
+    g.AddEdge("B", "D", 5)
+    g.AddEdge("C", "D", 1)
+    g.AddEdge("D", "E", 3)
+    g.AddEdge("E", "F", 2)
+
+    // Find the shortest distances from node "A" to all other nodes.
+    shortestDistances := Dijkstra(g, "A")
+
+    // Print the shortest distances.
+    for node, distance := range shortestDistances {
+        fmt.Printf("Shortest distance from A to %s: %v\n", node, distance)
+    }
+}