CareerCup

clear(int x,int n)
{
int k=1;
int mask=0;
mask=k<<(n-1);
x=x & (~mask);
return x;
}

k = 1;
for(int i = 0; i < n; i++)
k<<1;
m = k ^ 0;
input = m & input;

int mask =0 ;

mask | = 1<<(n-1);

x= x&(~mask);

int mask =0 ;

mask | = 1<<(n-1);

x= x&(~mask);

In the above solution, in place of "mask | = 1<<(n-1);" we can simply keep "mask = <<(n-1);". There is no need of using |=. Please correct me if I am wrong.

return nInput&(~(1<<(n-1)));

how about
mask=1;
mask<<n-1;
number=(number&mask)?(number^mask):number

int clear(int n, int num)
{
    num = 1<<(n-1) ^ num;
    return num;
}

All of these solutions are of order n where n is the bit to be cleared. This can, however, be done in constant time with a lookup table. Build a table (an array) that has a preset bitmask for each bit in the integer. The 'Clear' function then looks up the mask using the value of n passed in. The mask is then applied and the modified value of x returned.

O(n) is too much for a function like this that may be used many times. The lookup table solution is O(1).

int clear_n(int num,int n)
{
return (num = num&(~(1<<(n-1)));
}

n ^ (1<<(n-1))

Java Code:

public static int clearNthBit(int num, int nthBit){
		if(num == 0)
			return num;
		
		int k = 1<<(nthBit-1);
		if((num & k) >= 1){
			return num ^ k; //bit is set clear the bit
		} else {
			return num; //bit is clear
		}
	}

return ip&(~0-pow(2,n));

return ip&(~0-pow(2,n));

num &= (~0<<n)

num is integer
n bit want to disable

please correct me if im wrong

x=number/(10^n); //quotient
number=number-x*(10^n);

import java.lang.*;
import java.io.*;
import java util.*;
class toggle_n{
int n,b=1;

System.out.println("enter an number");
Scanner sc=new Scanner();
int a=sc.nextInt();

System.out.println("enter position to be toggle");
n=sc.nextInt();

b=b<<(n-1);
a=a^b;

System.out.println("number after toggling nth bit");
System.out.println(a);

}

//question 5 of java queston is to toggle nth bit 
import java.io.*;
import java.util.*;
import java.math.*;

   class toggle{

              public int i,j;
              int index=0,id=0;
              int binary[],binary2[];

              void toggling_nbit()throws IOException
                 {
                     System.out.println("ENTER A NUMBER ");
                     String s;
                     String p=" ";
                     BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
                     s=br.readLine();
                     int a=Integer.parseInt(s);       
                      binary = new int[40];
                      tobinary(a);
            
              System.out.println( ); 
              System.out.println("WHICH BIT U WANT TO TOGGLE");
                    s=br.readLine( );
                     int n=Integer.parseInt(s);
                     int b=1;
                     int c=0;
             System.out.println( );   
                     for(i=1;i<=n-1;i++)
                       {       System.out.println( ); 
                                System.out.println("SHIFT FACTOR" );      
                                System.out.println(c=(b<<i));
                       }
         
                    binary2=new int[40];
                    id = 0;
 
                           while(c> 0)
                             {
                                   binary2[id++] = c%2;
                                   c = c/2;
                              }

                           /*for( i = id-1;i >= 0;i--)
                                {        
                                  System.out.print(binary2[i]);
                                 }*/
            System.out.println( );   
                        xor(binary,binary2);

        }//toggling function closed
          
                void tobinary(int a)
                  {
                           while(a > 0)
                           {
                                binary[index++]= a%2;
                                  a=a/2;
                            }
                        System.out.println(" BINARY VALUE OF INPUT" );   

                           for( i = index-1;i >= 0;i--)
                              {       
                               System.out.print(binary[i]);
                              }

                  
                    }//to binary function vclosed


        
       void xor(int binary[],int binary2[])
        {
                  System.out.println("VALUE AFTER TOGGLE");
                  for(i=0;i<=index-1;i++)
                   {
                         if(binary[i]==binary2[i])
                               {binary[i]=0;}
                    
                           else
                          { binary[i]=1;}
                     }


                 for( i = index-1;i >= 0;i--){        //binary of input
                 System.out.print(binary[i]);
                 }

         }
     
   }//class closed


  class toggle_n{
           public static void main(String args[]) throws IOException{
              toggle t =new toggle( );
              t.toggling_nbit( );
              }//main closed

             }//class closed