Fixed sonar

Author: javadev

src/main/java/g3101_3200/s3161_block_placement_queries/Solution.java

@@ -93,7 +93,7 @@ public int query(int i) {
     }
 
     private static final class UnionFind {
-        public int[] parent;
+        private final int[] parent;
 
         public UnionFind(int n) {
             parent = new int[n];