Bit Manipulation Interview Questions and Practice Problems

opposite Signs.md

Detect if two integers have opposite sign on not.

// Detect if two integers have opposite sign on not.

#include <iostream>
#include <bitset>
using namespace std;

int main()
{
	int x = 4;
	int y = -8;

	cout << x << "  in binary is " << bitset<32>(x) << endl;
	cout << y << " in binary is " << bitset<32>(y) << endl;

	// true if x and y have opposite signs
	bool isOpposite = ((x ^ y) < 0);

	if (isOpposite)
		cout << x << " and " << y << " have opposite signs";
	else
		cout << x << " and " << y << " don't have opposite signs";

	return 0;
}

Q1. Check even or odd.cpp

// Check if a given integer is even or odd.
/* 
    n = 5 = 101(binary)   |  n = 6 = 0110
        1 = 001(binary)   |      1 = 0001
        ------------      |      --------
      & - 001 == 1 (true) |   &- 0000 == 0 (false) 
*/

#include<iostream>                             
using namespace std;

int main() {
  int n = 5;
  
  if(n & 1)
     cout<<n<<" is odd number"<<endl;
  else
    cout<<n<<" is even number"<<endl;
  
  return 0
}