/* package whatever; // don't place package name! */
 
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		System.out.println(hitungNomorBit(13, 0)); // 1
        System.out.println(hitungNomorBit(13, 1)); // 3
        System.out.println(hitungNomorBit(13, 2)); // 0 (pengganti null)
        System.out.println(hitungNomorBit(Integer.MAX_VALUE, 1)); // 31 bit 1
        System.out.println(hitungNomorBit(Integer.MIN_VALUE, 1)); // 1 bit 1 dari sign bit
        System.out.println(hitungNomorBit(0, 0)); // 1 bit 0
        System.out.println(hitungNomorBit(-1, 1)); // 32 bit 1
	}
 
	// asumsi angka adalah signed integer 32-bit dan leading zero tidak dihitung
    public static int hitungNomorBit(int angka, int nomorBit) {
        if (angka == 0 && nomorBit == 0) { // edge case untuk angka 0 dianggap sebagai 1 bit 0
            return 1;
        }
        int zeroCount = 0;
        int oneCount = 0;
        while (angka != 0) {
            if ((angka & 1) == 1) { // cek rightmost bit
                oneCount++;
            } else {
                zeroCount++;
            }
            angka >>>= 1; // unsigned right shift supaya bit kiri diisi 0
        }
        if (nomorBit == 0) {
            return zeroCount;
        } else if (nomorBit == 1) {
            return oneCount;
        } else {
            return 0; // tidak bisa return null karena return type di java harus seragam
        }
    }
}

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