#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
vector<int> decimalToBiner(int angka){
vector<int> biner;
if(angka == 0){
biner.push_back(0);
return biner;
}
while(angka > 0){
biner.push_back(angka%2);
angka /= 2;
}
reverse(biner.begin(), biner.end());
return biner;
}
int hitungNomorBit(int angka, int nomorBit){
if(nomorBit != 1 && nomorBit != 0){
return -1;
}
vector<int> biner = decimalToBiner(angka);
int count = 0;
for(int digit : biner){
if(digit == nomorBit){
count++;
}
}
return count;
}
void tc(int angka, int nomorBit){
int count = hitungNomorBit(angka, nomorBit);
if (count == -1) cout << "null\n";
else cout << count << "\n";
}
int main() {
// int t; cin >> t;
// while(t--){
// solve();
// }
tc(13, 0);
tc(13, 1);
tc(13, 2);
return 0;
}
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