HackerEarth Maximum bit shifts problem solution

In this HackerEarth Maximum bit shifts, problem-solution you are given a sequence of N numbers. You can perform the following operation:

Select a number from the sequence and swap any pair of bits in its binary representation (Binary representation does not have any leading zeroes).

Output the lexicographic maximum sequence possible after performing 0 or more of the above operations.

import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.IOException;
import java.io.InputStream;

public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task {
        PrintWriter out;
        InputReader in;

        public void solve(int testNumber, InputReader in, PrintWriter out) {
            this.out = out;
            this.in = in;
            int n = ni();
            long[] arr = new long[n];
            long[] ans = new long[n];
            int i = 0;
            for (i = 0; i < n; i++) {
                arr[i] = nl();
                String st = Long.toBinaryString(arr[i]);
                int c = 0;
                for (int j = 0; j < st.length(); j++)
                    c += st.charAt(j) - '0';
                String mx = "";
                for (int j = 0; j < c; j++)
                    mx += '1';
                for (int j = 0; j < st.length() - c; j++)
                    mx += '0';
                ans[i] = Long.parseLong(mx, 2);
            }
            for (i = 0; i < n; i++)
                p(ans[i] + " ");
            pn("");
        }

        int ni() {
            return in.nextInt();
        }

        long nl() {
            return in.nextLong();
        }

        void pn(String zx) {
            out.println(zx);
        }

        void p(Object o) {
            out.print(o);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new UnknownError();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new UnknownError();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public String next() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuffer res = new StringBuffer();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));

            return res.toString();
        }

        private boolean isSpaceChar(int c) {
            return c == ' ' || c == 'n' || c == 'r' || c == 't' || c == -1;
        }

    }
}