Count the Number of Bits

Count the Number of Bits needed to be Flipped to Integer X to Generate Integer Y

#include 

#include 

#define num_bits_int (sizeof(int)*8)

void main()

{

    int n, m, i, count = 0, a, b;

    printf("Enter the number\n");

    scanf("%d", &n);

    printf("Enter another number\n");

    scanf("%d", &m);

    for (i = num_bits_int-1;i >= 0;i--)

    {

        a = (n >> i)& 1;

        b = (m >> i)& 1;

        if (a != b)

            count++;

    }

    printf("flip count = %d\n", count); 

    getch();

}

Output

Enter the number

127

Enter another number

125

flip count = 1

Enter the number

127

Enter another number

128

flip count = 8

Enter the number

42

Enter another number

21

flip count = 6

Identify the Missing Number in an Integer Array of Size N-1 with Numbers[1,N]

#include 

#include 

#define max 15

int missing_number_array(int [],int);

int main()

{

    int a[max], num, i, n;

    clrscr();

    printf("enter the range of array\n");

    scanf("%d", &n);

    for (i = 0;i < n;i++)

    {

        printf("enter a[%d]element into the array:", i);

        scanf("%d", &a[i]);

    }

    num = missing_number_array(a, n);

    printf("The missing number -> %d\n", num);

}

int missing_number_array(int a[],  int n)

{

    int i;

    int s1 = 0; 

    int s2 = 0; 

    for (i = 0;i < n;i++)

        s1 = s1 ^ a[i];

    for (i = 1;i <= n + 1;i++)

        s2 = s2 ^ i; 

    return (s1 ^ s2); 

    getch();

}

Output

enter the range of array

9

enter a[0]element into the array:1

enter a[1]element into the array:5

enter a[2]element into the array:2

enter a[3]element into the array:7

enter a[4]element into the array:3

enter a[5]element into the array:4

enter a[6]element into the array:10

enter a[7]element into the array:9

enter a[8]element into the array:6

The missing number -> 8

enter the range of array

4

enter a[0]element into the array:1

enter a[1]element into the array:5

enter a[2]element into the array:3

enter a[3]element into the array:2

The missing number -> 4

enter the range of array

4

enter a[0]element into the array:3

enter a[1]element into the array:2

enter a[2]element into the array:5

enter a[3]element into the array:4

The missing number -> 1