C Bit Pro

Find the Highest Bit Set for any given Integer

#include 

#define num_bits sizeof(int)*8

int highest_bit_set(int);

void display(int);

int i = num_bits;

void main()

{

    int num, pos;

    printf("\nenter the number:");

    scanf("%d", &num);

    display(num);

    pos = highest_bit_set(num);

    printf("\nthe position of the highest bit set is %d", pos);

}

int highest_bit_set(int num)

{

    int count = 0;

    while (num >> 1 != 0)

    {

        count++;

        num = num >> 1;

    }

    return(count);

}

void display(int num)

{

    int c;

    c = num & 1;

    if (i > 0)

    {

        i--;

        display(num >> 1);

    }

    printf("%d", c);

}

Output

Enter the number:10000

000000000000000000010011100010000

The position of the highest bit set is 13

 Count Number of bits set to 0 in an Integer

#include 

#include 

#define num_bits_int (8*sizeof(int))

int count_unset(int);

int main()

{

    int i, num, snum, res, count = 0;

    clrscr();

    printf("\nEnter the number");

    scanf("%d", &num);

    for (i = 0;i <= num_bits_int;i++)

    {

        snum = num >> i;

        res = snum & 1;

        if (res == 0)

            count++;

    }

    printf("%d", count); 

    getch();

}

Output

Enter the number128

31

Enter the number -127

6

Replace Bits in Integer from Specified Positions from Another Integer

#include 

#include 

void replace_bits(int, int, int, int);

 int main()

{

    int number_x, number_y, start_pos, end_pos;

    clrscr();

    printf("\nEnter the number x in hexa decimal ");

    scanf("%x", &number_x);

    printf("\nEnter the number y in hexa decimal");

    scanf(" %x", &number_y);

    printf("\nEnter value for a");

    scanf("%d", &start_pos);

    printf("\nEnter value for b");

    scanf("%d", &end_pos);

    replace_bits(number_x, number_y, start_pos, end_pos);

}

void replace_bits(int number_x, int number_y, int start_pos, int end_pos)

{

    int i, shift_y, ybit;

    long int temp, t;

    for (i = start_pos;i <= end_pos;i++)

    {

        shift_y = number_y >> i;

        ybit = shift_y & 1;

        if (ybit == 1)

        {

            temp = 1 << i;

            number_x = number_x | temp;

        }

        if (ybit == 0)

        {

            t = 0XFFFFFFFF;

            temp = 1 << i;

            start_pos = t ^ temp;

            number_x = number_x & start_pos;

        }

    }

    printf("%x",   number_x);

    getch();

}

Output

Enter the number x in hexa decimal 11223344

Enter the number y in hexa decimal55667788

Enter value for a12

Enter value for b19

11267344

Byte as Input and returns all the Bits between given Positions

#include 

#include 

int number_between_bit_positions(int,int,int);

int result = 0;

int main()

{

    int number, start_pos, end_pos;

    clrscr();

    printf("\nEnter the number");

    scanf("%d", &number);

    printf("\nEnter the position of a and b");

    scanf("%d %d", &start_pos, &end_pos);

    result = number_between_bit_positions(number, start_pos, end_pos);

    printf("Byte Equivalent of bits between %d and %d positions %d", start_pos, end_pos, result);

}

int number_between_bit_positions(int number, int start_pos , int end_pos)

{

    int i, j, shift_num, res_val;    

    for (i = start_pos, j = 0;i <= end_pos;i++,j++)

    {

        shift_num = number >> i;

        res_val = shift_num & 1;

        res_val = res_val << j;

        result += res_val;

    }

    return result; 

    getch();

}

Output

   

   Enter the number78

Enter the position of a and b

3

6

Byte Equivalent of bits between 3 and 6 positions is 9

Swap the ith and jth Bits for a 32 Bit Integer

#include 

#include 

int swap(int ,int);

int number, pos1, pos2;

int main()

{

    int result, shift_pos1, shift_pos2;

    clrscr();

    printf("\nEnter Number");

    scanf("%d", &number);

    printf("\nEnter bit positions to swap");

    scanf("%d %d", &pos1, &pos2);

    shift_pos1 = number >> pos1;

    shift_pos2 = number >> pos2;

    result = swap(shift_pos1&1, shift_pos2&1);

    printf("%d\n", result);

}

 int swap(int pos1_val, int pos2_val)

{

    int temp1, temp2;

    long int base, base1;

    if (pos1_val == 1)

    { 

        base1 = 1 << pos2;

        number = number + base1;

    }

    if (pos2_val == 1)

    {

        base1 = 1 << pos2;

        number = number + base1;

    }

    if (pos1_val == 0)

    {

        base = 0XFFFFFFFF;

        base1 = 1 << pos2;

        temp1 = base ^ base1;

        number = number & temp1;

    }

    if (pos2_val == 0)

    {

        base = 0XFFFFFFFF;

        base1 =  1 << pos1;

        temp2 = base ^ base1;

        number = number & temp2;

    }

    return number;

    getch();

}

Output

Enter Number101

Enter bit positions to swap2 4

113