How to store 1e100 number in java (like python example)?

Question

I need to output: yes if N is a direct power of 2 and no otherwise, where 1 <= N <= 1e100

Same in Python code:

n=int(input())
if(n!=0 and (n&(n-1)==0)):
    print("yes")
else:
    print("no")

Answer 1

You can use BigInteger to store arbitrarily large integers.

Scanner sc = new Scanner(System.in);
BigInteger n = new BigInteger(sc.nextLine());
if(!n.equals(BigInteger.ZERO) && n.and(n.subtract(BigInteger.ONE)).equals(BigInteger.ZERO)){
   System.out.println("yes");
} else {
   System.out.println("no");
}

Demo!

Answer 2

In Java, you have to use the BigInteger class for integers this big. This class also has several convenient methods to work with the binary representation of this number.

For example, you can use bitCount to determine if number is a power of 2:

boolean isPowerOf2(BigInteger integer) {
    return integer.bitCount() == 1;
}

Usage:

var integer = new BigInteger("1267650600228229401496703205376");
if (isPowerOf2(integer)) System.out.println("yarp");
else System.out.println("nope");