A pernicious number is a positive integer which has prime number of ones in its binary representation.
PROGRAM
// C++ Program to check given number is Pernicious or not
#include <iostream>
#include <bitset>
#include <cassert>
using namespace std;
bool isPrime(int num)
{
if(num == 1)
return false;
for(int j=2 ; j<=(num/2) ; j++)
{
if(num % j == 0)
return false;
}
return true;
}
int main()
{
long num, count = 0;
cout << "ENTER A NUMBER : ";
cin>>num;
assert(num > 0);
string binary = bitset<8>(num).to_string();
for(int i=0 ; i < binary.length(); i++)
{
if(binary[i] == '1')
count++;
}
if(isPrime(count))
cout<<endl<<num<<" IS A PERNICIOUS NUMBER";
else
cout<<endl<<num<<" IS NOT A PERNICIOUS NUMBER";
return 0;
}
OUTPUT
