counting number of bits

java/counting number of bits.java

@@ -0,0 +1,61 @@
+// counting number of bits
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.*;
+
+public class Main
+{
+    private static BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+    private static Integer K, N;
+    private static List<Integer> numbers;
+
+    public static void main(String[] er)
+    {
+        try
+        {
+            Integer T = Integer.parseInt(bufferedReader.readLine());
+
+            for (int i=0; i<T; ++i)
+            {
+                String[] input = bufferedReader.readLine().split(" ");
+                N = Integer.parseInt(input[0]);
+                K = Integer.parseInt(input[1]);
+
+                numbers = new ArrayList<>();
+                TreeSet<Integer> counts = new TreeSet<>();
+                String[] inputs = bufferedReader.readLine().split(" ");
+                for(String s : inputs)
+                {
+                    counts.add(countFor(Integer.parseInt(s)));
+                }
+
+                int count = 0;
+                while (K > 0)
+                {
+                    count += counts.pollLast();
+                    --K;
+                }
+                System.out.println(count);
+            }
+        }
+        catch (Exception e)
+        {
+            System.out.print("exception in buffered reader " + e.getMessage());
+        }
+
+    }
+
+    private static Integer countFor(Integer i)
+    {
+        Integer count = 0;
+
+        while (i > 0)
+        {
+            i = i&(i-1);
+            ++count;
+        }
+
+        return count;
+    }
+}