Initial data commit

Task/Dijkstras-algorithm/JavaScript/dijkstras-algorithm.js

@@ -0,0 +1,85 @@
+const dijkstra = (edges,source,target) => {
+    const Q = new Set(),
+          prev = {},
+          dist = {},
+          adj = {}
+
+    const vertex_with_min_dist = (Q,dist) => {
+        let min_distance = Infinity,
+            u = null
+
+        for (let v of Q) {
+            if (dist[v] < min_distance) {
+                min_distance = dist[v]
+                u = v
+            }
+        }
+        return u
+    }
+
+    for (let i=0;i<edges.length;i++) {
+        let v1 = edges[i][0],
+            v2 = edges[i][1],
+            len = edges[i][2]
+
+        Q.add(v1)
+        Q.add(v2)
+
+        dist[v1] = Infinity
+        dist[v2] = Infinity
+
+        if (adj[v1] === undefined) adj[v1] = {}
+        if (adj[v2] === undefined) adj[v2] = {}
+
+        adj[v1][v2] = len
+        adj[v2][v1] = len
+    }
+
+    dist[source] = 0
+
+    while (Q.size) {
+        let u = vertex_with_min_dist(Q,dist),
+            neighbors = Object.keys(adj[u]).filter(v=>Q.has(v)) //Neighbor still in Q
+
+        Q.delete(u)
+
+        if (u===target) break //Break when the target has been found
+
+        for (let v of neighbors) {
+            let alt = dist[u] + adj[u][v]
+            if (alt < dist[v]) {
+                dist[v] = alt
+                prev[v] = u
+            }
+        }
+    }
+
+    {
+        let u = target,
+        S = [u],
+        len = 0
+
+        while (prev[u] !== undefined) {
+            S.unshift(prev[u])
+            len += adj[u][prev[u]]
+            u = prev[u]
+        }
+        return [S,len]
+    }
+}
+
+//Testing algorithm
+let graph = []
+graph.push(["a", "b", 7])
+graph.push(["a", "c", 9])
+graph.push(["a", "f", 14])
+graph.push(["b", "c", 10])
+graph.push(["b", "d", 15])
+graph.push(["c", "d", 11])
+graph.push(["c", "f", 2])
+graph.push(["d", "e", 6])
+graph.push(["e", "f", 9])
+
+let [path,length] = dijkstra(graph, "a", "e");
+console.log(path) //[ 'a', 'c', 'f', 'e' ]
+console.log(length) //20