long bin2dec(char *s)
{
   long r=0;
   for (; *s; r = (r<<1) | (*s++ - '0'));
   return r;
 }

/*conversion of binary number to decimal*/
#include <stdio.h>
 
int main()
{
	int binary, digit, base = 0, decimal = 0;
	printf("enter a binary number: ");
	scanf("%d", &binary);
	printf("Entered binary number is: %d\n", binary);
	while(binary)
	{
		digit = binary % 10;
		decimal += digit << base;
		base += 1;
		binary /= 10;
	}
	printf("decimal equivalent of the entered binary number is: %d", decimal);
	return 0;
}

#include<stdio.h>
void main()
 
{
 
	long int deci,rem,bin,p=1;
	printf("enter no");
	scanf("%ld",&deci);
	if (deci > 0)
 
	{
		while (deci > 0)
 
		 {
			rem=deci%2;
			bin=rem*p+bin;
			p=p*10;
			deci=deci%2;
 
			}
			printf("binary no is %ld",bin);
				//end of while loop
 
			getchar();
 
			}
 
			//end of condition
 
			else
 
				printf("binary no for +tive integer only");
 
				getchar();
 
 
				}