Question

a) The following program is supposed to convert a binary number to its decimal equivalent. Modify the program so that it does the job.(15 points) b) How would you create the executable file of the program (file name: b2d.c) in Linux? (5 points) #include <stdio.h> int main (void) int binary: printf("Enter a binary number:\n"); scanf("%d", &binary): int nofDigit = 0, remain = binary: while (remain > 0) - remain = remain/10; nofDigit++; int digit, dval = 0, bx = binary: for (int k = 0; k < nofDigit: k++) digit = bx % 2.0 bx /= 10; dVal = digit* pow(2. k); k++; printf("The decimal value of the binary number is %d\n", dval),

Answer 1

Answer a) Code:

#include <stdio.h> // header file for basic input output operation
#include<math.h> // header file for math functions like pow()

int main() { // main fucntion
int binary; // variable that stores the binary number
printf("Enter a binary number:\n");
scanf("%d" , &binary); // user input
  
int nofDigit = 0, remain = binary, check = 0, tmp; // variable to store number of digits and remaining number number on integer division by 10
while(remain/10){
tmp = remain % 10;
remain = remain / 10;
// following contion is to set check flag 1 if the entered number is binary and set to 0 if entered number is not binary number
if(tmp == 0 || tmp == 1){
check = 1;
}else{
check = 0;
break; // break of any other integer is found other than 0 and 1
}
nofDigit++; // countung the digits present in the binary number
} // end of while loop
if (check == 0){ // check if user has entered binary number or not.
printf("Error: Binary number only contains 0s and 1s\n");
return 1;
}
int digit, dVal= 0, bx = binary; // variable to store digit in binary number and decimal value
for( int k =0; k<=nofDigit; k++){
digit = bx % 10; // getting the last digit in bx
bx /= 10; // dividing by 10
dVal += digit * pow(2,k); // calculating decimal value eg

} // end of for loop
printf("The decimal value of the binary number is %d\n", dVal); // printing the result
}

Smaple output:

root@kali:-/code# gcc b2d.c -o b2d - Im root@kali:-/code# ./b2d Enter a binary number: 1001 The decimal value of the binary number is 9 root@kali:-/code# /b2d Enter a binary number: 1010 The decimal value of the binary number is 10 root@kali:-/code# ./b2d Enter a binary number: 1020 Error: Binary number only contains Os and is root@kali:-/code# I

Answer b:

gcc b2d.c -o b2d -lm

Explanation: we need to use the -lm flag to link the math library to the program if we do not use -lm(l for Long) flag we may get following error:

undefined reference to `pow'

error: ld returned 1 exit status

here gcc is the compiler and b2d.c is code file name and -o flag provide us the option to give the name of the output executable file if we do not use -o flag compiler will create a.out executable file in current working directory.

Note: Please let me know if you have any doubt.