fix formatting issues

Author: lennart

src/main/java/com/thealgorithms/tree/CentroidDecomposition.java

@@ -50,7 +50,7 @@ public CentroidDecomposition(int n, int startingNode) {
             throw new IllegalArgumentException("Starting node must be in range 0.." + (n - 1) + " but got " + startingNode);
         }
         this.startingNode = startingNode;
-        for (int i = 0; i < n; i++){
+        for (int i = 0; i < n; i++) {
             centroidParent[i] = -1;
             tree[i] = new ArrayList<>();
             centroidTree[i] = new ArrayList<>();
@@ -139,7 +139,7 @@ public void findCentroid(int src, int previousCentroid) {
 
         for (int node : tree[src]) {
             if (centroidMarked[node]) continue;
-            if (subtreeSizes[node] > (treeSize/2)) {
+            if (subtreeSizes[node] > (treeSize / 2)) {
                 heavyChild = node;
                 break;
             }
@@ -158,16 +158,16 @@ public void findCentroid(int src, int previousCentroid) {
 
         for (int node : tree[src]) {
             if (!centroidMarked[node]) findCentroid(node, src);                
-            }
         }
+    }
 
     /**
      * Applies the given action to all centroid ancestors of the given node,
      * including the node itself, walking up via centroidParent[] until the root.
      */
     public void forEachAncestor(int centroid, IntConsumer action) {
         int curr = centroid;
-        while (curr != -1){
+        while (curr != -1) {
             action.accept(curr);
             curr = getParent(curr);
         }

src/test/java/com/thealgorithms/tree/CentroidDecompositionTest.java

@@ -81,7 +81,7 @@ void invalidStartingNodeThrows() {
 
     @Test
     void IllegalArgumentThrows() {
-        assertThrows(IllegalArgumentException.class, () -> { new CentroidDecomposition(10, 99);});
+        assertThrows(IllegalArgumentException.class, () -> { new CentroidDecomposition(10, 99); });
     }
 
     @Test