This program adds two binary numbers in the C programming language.

## Problem Statement

Given two binary numbers as input, write a C program to add them and print the result.

## Solution

To solve this problem, we will first convert the binary numbers to decimal numbers using the following algorithm:

- Initialize a variable
`result`

to 0. - Iterate over each digit of the binary number from right to left.
- For each digit, if it is 1, add 2^(index) to
`result`

, where`index`

is the position of the digit starting from 0. - Return the final value of
`result`

.

Once we have converted both binary numbers to decimal numbers, we can simply add them using the `+`

operator and convert the result back to a binary number. Here’s the code:

#include <stdio.h> int binaryToDecimal(long long binary); long long decimalToBinary(int decimal); int main() { long long binary1, binary2; int decimal1, decimal2, sum; printf("Enter the first binary number: "); scanf("%lld", &binary1); printf("Enter the second binary number: "); scanf("%lld", &binary2); decimal1 = binaryToDecimal(binary1); decimal2 = binaryToDecimal(binary2); sum = decimal1 + decimal2; printf("Sum of %lld and %lld is %lld in binary.\n", binary1, binary2, decimalToBinary(sum)); return 0; } int binaryToDecimal(long long binary) { int decimal = 0, index = 0; while (binary != 0) { int digit = binary % 10; decimal += digit * (1 << index); binary /= 10; index++; } return decimal; } long long decimalToBinary(int decimal) { long long binary = 0, place = 1; while (decimal != 0) { binary += (decimal % 2) * place; decimal /= 2; place *= 10; } return binary; }

Let’s go through the code step-by-step:

- We include the standard input/output header file
`stdio.h`

. - We declare two functions called
`binaryToDecimal()`

and`decimalToBinary()`

. The`binaryToDecimal()`

function takes a long long integer argument`binary`

and returns its decimal equivalent. The`decimalToBinary()`

function takes an integer argument`decimal`

and returns its binary equivalent as a long long integer. - In the
`main()`

function, we declare four variables:`binary1`

and`binary2`

are the two binary numbers entered by the user,`decimal1`

and`decimal2`

are their decimal equivalents, and`sum`

is their sum in decimal form. - We prompt the user to enter the two binary numbers using the
`printf()`

and`scanf()`

functions. - We convert both binary numbers to decimal form using the
`binaryToDecimal()`

function. - We add the decimal equivalents of the binary numbers using the
`+`

operator to get their sum in decimal form. - We convert the decimal sum back to a binary number using the
`decimalToBinary()`

function and print it using the`printf()`

function.

The `binaryToDecimal()`

function takes a binary number as input and converts it to decimal form using the algorithm described above. It iterates over each digit of the binary number from right to left using a while loop. For each digit, it multiplies 2^(index) by the value of the digit (0 or 1) and adds the result to

the `decimal`

variable. It also increments the `index`

variable for each digit. Finally, it returns the decimal equivalent of the binary number.

The `decimalToBinary()`

function takes a decimal number as input and converts it to binary form using the algorithm described above. It iterates over each bit of the binary number from right to left using a while loop. For each bit, it computes the remainder of the division by 2 (0 or 1) and multiplies it by a place value (`place`

) that starts at 1 and doubles with each iteration. It adds the result to the `binary`

variable and divides the decimal number by 2, discarding the remainder. Finally, it returns the binary equivalent of the decimal number.

## Output

## Explanation

Let’s say the user enters the binary numbers 1101 and 10011. The `main()`

function prompts the user to enter the two binary numbers using the `printf()`

and `scanf()`

functions. Then it calls the `binaryToDecimal()`

function to convert the binary numbers to decimal form and adds them using the `+`

operator to get their sum in decimal form.

The `binaryToDecimal()`

function converts the first binary number (1101) to its decimal equivalent (13) using the following algorithm:

- The
`decimal`

variable is initialized to 0 and the`index`

variable is initialized to 0. - The while loop iterates as long as the binary number is not 0.
- The
`digit`

variable is set to the remainder of the binary number divided by 10 (which is 1). - The decimal equivalent of the digit is computed by multiplying it by 2^(index) (which is 1, since index is 0).
- The result is added to the
`decimal`

variable (which becomes 1). - The binary number is divided by 10, discarding the last digit (which becomes 110).
- The
`index`

variable is incremented by 1 (which becomes 1). - Steps 3-7 are repeated for each digit of the binary number.
- The
`decimal`

variable is returned (which is 13).

The `binaryToDecimal()`

function then converts the second binary number (10011) to its decimal equivalent (19) using the same algorithm.

The `main()`

function adds the decimal equivalents of the two binary numbers (13 + 19 = 32) and calls the `decimalToBinary()`

function to convert the decimal sum back to a binary number.

The `decimalToBinary()`

function converts the decimal number 32 to its binary equivalent (100000) using the following algorithm:

- The
`binary`

variable is initialized to 0 and the`place`

variable is initialized to 1. - The while loop iterates as long as the decimal number is not 0.
- The remainder of the decimal number divided by 2 (which is 0) is computed and multiplied by the
`place`

variable (which is 1). - The result is added to the
`binary`

variable (which becomes 0). - The decimal number is divided by 2, discarding the remainder (which becomes 16).
- The
`place`

variable is doubled (which becomes 2). - Steps 3-6 are repeated for each bit of the binary number.
- The
`binary`

variable is returned (which is 100000).

The `main()`

function then prints the binary sum using the `printf()`

function (which is 100000 in this case).

## Conclusion

In this program, we have seen how to add two binary numbers in the C programming language. We first converted the binary numbers to decimal form , then added them using the `+`

operator, and finally converted the decimal sum back to binary form. We used two separate functions to convert binary to decimal and decimal to binary, each implementing a different algorithm. The program demonstrates the use of loops, variables, and functions in C, as well as the conversion between different number systems.

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