Merge pull request #88 from Weltenbummler397/exercism-sync/5ed613ca78a9a50a

[Sync Iteration] java/relative-distance/1

solutions/java/relative-distance/1/src/main/java/RelativeDistance.java

@@ -0,0 +1,75 @@
+import java.util.List;
+import java.util.*;
+
+class RelativeDistance {
+
+    Map<String, List<String>> familyTree = new HashMap<>();
+    
+        RelativeDistance(Map<String, List<String>> familyTree) {
+        for (Map.Entry<String, List<String>> entry : familyTree.entrySet()) {
+            String parent = entry.getKey();
+            List<String> children = entry.getValue();
+            
+            if (!this.familyTree.containsKey(parent)) {
+                this.familyTree.put(parent, new ArrayList<>());
+            }
+            
+            for (String child : children) {
+                if (!this.familyTree.containsKey(child)) {
+                    this.familyTree.put(child, new ArrayList<>());
+                }
+                
+                this.familyTree.get(parent).add(child);
+                this.familyTree.get(child).add(parent);
+            }
+            
+            for (int i = 0; i < children.size(); i++) {
+                for (int j = i + 1; j < children.size(); j++) {
+                    String sibling1 = children.get(i);
+                    String sibling2 = children.get(j);
+                    
+                    this.familyTree.get(sibling1).add(sibling2);
+                    this.familyTree.get(sibling2).add(sibling1);
+                }
+            }
+        }
+    }
+
+    int degreeOfSeparation(String personA, String personB) {
+        if (personA.equals(personB)) {
+            return 0;
+        } else if (!familyTree.containsKey(personA)) {
+            return -1;
+        } else if (!familyTree.containsKey(personB)) {
+            return -1;
+        }
+
+        Queue<String> queue = new LinkedList<>();
+        Queue<Integer> distances = new LinkedList<>();
+        HashSet<String> visited = new HashSet<>();
+
+        queue.add(personA);
+        distances.add(0);
+        visited.add(personA);
+
+        while (!queue.isEmpty()) {
+            String currentPerson = queue.poll();
+            int currentDistance = distances.poll();
+
+            if (currentPerson.equals(personB)) {
+                return currentDistance;
+            }
+
+            List<String> nachbarn = familyTree.get(currentPerson);
+
+            for (String nachbar : nachbarn) {
+                if (!visited.contains(nachbar)) {
+                    visited.add(nachbar);
+                    queue.add(nachbar);
+                    distances.add(currentDistance + 1);
+                }
+            }
+        }
+        return -1;
+    }
+}