C program to convert Decimal to Binary [closed] - c

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I've written a program in C to convert Decimal numbers to Binary and store it in a string. The issue is not the binary that's printed in reverse but how the output is displayed
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main()
{
int decimal;
// get the decimal from user
printf("Enter the decimal number: ");
scanf("%i", &decimal);
if(decimal == 1)
printf("The binary equivalent of %i is %i\n", decimal, decimal);
else
{
// considering binary is 64 bits in total
char bit[64];
int dividend, remainder, counter;
// we need decimal value intact so dividend copies it
dividend = decimal;
counter = 0;
do
{
remainder = dividend % 2;
if(remainder != 0)
bit[counter] = putchar('1');
else
bit[counter] = putchar('0');
// update the dividend and counter
dividend /= 2;
++counter;
// break if dividend has reached 1
if(dividend == 1)
break;
} while(dividend);
// print the final result
printf("The binary equivalent of %i is %s\n", decimal, bit);
}
return(0);
}
The output of 2 (that should be 01 in reverse) gives something like this
$ 0The binary equivalent of 2 is 0time
for decimal 3
$ 1The binary equivalent of 3 is 1time

Answer 1

We beginners should help each other.:)
Here you are.
#include <stdio.h>
int main(void)
{
unsigned int decimal;
// get the decimal from user
printf("Enter the decimal number: ");
scanf("%u", &decimal);
// considering binary is 64 bits in total
char bit[64];
unsigned int dividend, remainder, counter;
// we need decimal value intact so dividend copies it
dividend = decimal;
counter = 0;
do
{
remainder = dividend % 2;
bit[counter++] = remainder + '0';
} while( dividend /= 2 );
bit[counter] = '\0';
// print the final result
printf("The binary equivalent of %u is %s\n", decimal, bit);
return 0;
}
The program output might look like
Enter the decimal number: 2
The binary equivalent of 2 is 01
As for your code then this code snippet
if(decimal == 1)
printf("The binary equivalent of %i is %i\n", decimal, decimal);
else
is redundant.
This code snippet
if(remainder != 0)
bit[counter] = putchar('1');
else
bit[counter] = putchar('0');
does not make sense. As it is shown in the demonstrative program above what you need is to write
bit[counter++] = remainder + '0';
This exit from the loop
if(dividend == 1)
break;
is wrong.
You also need to append the resulted string with a terminating zero.
Also as you do not take into account the sign of the entered number then it is better to declare it as having type unsigned int.
Take into account that headers <string.h> and <stdlib.h> are redundant and may be removed.

Answer 2

You need to change
if(dividend == 1)
to
if(dividend == 0)
Also memset bit to 0 prior to using it ie memset(bit,'\0',sizeof(bit)); before the loop