GeeksforGeeks

GeeksforGeeks » Interview Questions

In any given number, how to swap two consequtive bits

(4 posts)

1. 

   abhi4eternity
   Member
   Posted 7 months ago #
   
   

   Consider a number whose binary representation is : 10110010.
   To represent it more clearly if represented as pairs of two bits the number would be : 10-11-00-10
   After Swappiing the result should be : 01-11-00-01.

   Please provide a generic solution which could be valid for a number of any size(1 byte, 2byte, 4 byte)

2. 

   Anil Purohit
   guest
   Posted 7 months ago #
   
   

   n is the no to be changed.

   count=0;
   num=0;
   while(n>0)
   {
   t1=n&1;
   n=n>>1;
   t2=n&1;
   n=n>>1;

   t3=0;
   t3=t3|t1;
   t3=t3<<1;
   t3=t3|t2;

   t3=t3<<count;
   count+=2;
   num=num|t3;

   }

   printf("\n%d",num);

3. 

   gaurav
   guest
   Posted 7 months ago #
   
   

   let the no in a;
   b= a | 01 01 01 01 (in binary)
   c = a | 10 10 10 10(in binary)
   b<<1;
   c>>1;
   add b and c = output

4. 

   Guddu Sharma
   Member
   Posted 1 month ago #
   
   

   int main()
   {
   	int n,k,i,bit1,bit2;
   	printf("Enter n ");
   	scanf("%d",&n);
   	k=n;
   	i=0;
   	while(k)
   	{
   		if(bit1=(n&(1<<i)))
   			n&=~(1<<i);
   		if(bit2=(n&(1<<(i+1))))
   			n&=~(1<<(i+1));
   
   		if(bit1 && bit2)
   		{
   			n|=(1<<i);
   			n|=(1<<(i+1));
   		}
   		else if(bit1)
   			n|=1<<(i+1);
   		else if(bit2)
   			n|=1<<i;
   
   		i+=2;
   		k>>=2;
   	}
   	printf("%d",n);
   	return 0;
   }

   Let me know if there is any better approach

Reply

You must log in to post.

RSS feed for this topic