[KTLN-676] Add samples

timis1 · Apr 14, 2024 · 3e04bd3 · 3e04bd3
1 parent 1ab2f81
commit 3e04bd3
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Showing 2 changed files with 28 additions and 15 deletions.
diff --git a/core-kotlin-modules/core-kotlin-10/src/main/kotlin/com/baeldung/dijkstra/Dijkstra.kt b/core-kotlin-modules/core-kotlin-10/src/main/kotlin/com/baeldung/dijkstra/Dijkstra.kt
@@ -20,4 +20,27 @@ fun dijkstra(graph: Map<Int, List<Pair<Int, Int>>>, start: Int): Map<Int, Int> {
         }
     }
     return distances
-}
+}
+
+fun dijkstraWithLoops(graph: Map<Int, List<Pair<Int, Int>>>, start: Int): Map<Int, Int> {
+    val distances = mutableMapOf<Int, Int>().withDefault { Int.MAX_VALUE }
+    val priorityQueue = PriorityQueue<Pair<Int, Int>>(compareBy { it.second })
+    val visited = mutableSetOf<Pair<Int, Int>>()
+
+    priorityQueue.add(start to 0)
+    distances[start] = 0
+
+    while (priorityQueue.isNotEmpty()) {
+        val (node, currentDist) = priorityQueue.poll()
+        if (visited.add(node to currentDist)) {
+            graph[node]?.forEach { (adjacent, weight) ->
+                val totalDist = currentDist + weight
+                if (totalDist < distances.getValue(adjacent)) {
+                    distances[adjacent] = totalDist
+                    priorityQueue.add(adjacent to totalDist)
+                }
+            }
+        }
+    }
+    return distances
+}
diff --git a/core-kotlin-modules/core-kotlin-10/src/test/kotlin/com/baeldung/dijkstra/DijkstraUnitTest.kt b/core-kotlin-modules/core-kotlin-10/src/test/kotlin/com/baeldung/dijkstra/DijkstraUnitTest.kt
@@ -8,20 +8,10 @@ class DijkstraUnitTest {
     @Test
     fun `Should calculate shortest path when using Dijkstra algorithm`() {
         val graph = mapOf(
-            1 to listOf(
-                Pair(2, 10),
-                Pair(3, 15)
-            ),
-            2 to listOf(
-                Pair(4, 12)
-            ),
-            3 to listOf(
-                Pair(4, 15)
-            ),
-            4 to listOf(
-                Pair(5, 12),
-                Pair(6, 15)
-            ),
+            1 to listOf(Pair(2, 10), Pair(3, 15)),
+            2 to listOf(Pair(4, 12)),
+            3 to listOf(Pair(4, 15)),
+            4 to listOf(Pair(5, 12),Pair(6, 15)),
             5 to emptyList(),
             6 to emptyList()
         )