// Nazar Abdul Fattah
// Suitmedia - Backend Developer Test
 
function hitungNomorBit(angka, nomorBit) {
    if (nomorBit !== 0 && nomorBit !== 1) return null;
    if (angka === 0) return nomorBit === 0 ? 1 : 0;
 
    let count = 0;
    while (angka > 0) {
        if ((angka % 2) === nomorBit) count++;
        angka = Math.floor(angka / 2);
    }
 
    return count;
}
 
print(hitungNomorBit(13, 0)); // Output: 1
print(hitungNomorBit(13, 1)); // Output: 3
print(hitungNomorBit(13, 2)); // Output: null
 

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