Binary to Decimal C Program

binary_to_decimal.c

#include<stdio.h>

/*
* Function to convert a given binary number to
* its decimal equivalent.
*/
int binary_to_decimal(int num) {
	int rem, base = 1, decimal_number = 0;
	while( num > 0) {
		rem = num % 10;
		if((rem == 0) || (rem == 1)) {
			decimal_number = decimal_number + rem * base;
			num = num / 10 ;
			base = base * 2;
		} else {
			return -1; // Invalid binary number
		}
	}
	return decimal_number;
}

int main() {
	long int binary_number, decimal_number;
	printf("Enter any binary number : ");
	
	scanf("%ld", &binary_number);
	
	decimal_number = binary_to_decimal(binary_number);
	
	if(decimal_number != -1) {
		printf("The decimal equivalent value of binary %ld is: %ld", 
			binary_number, decimal_number);
	} else {
		printf("\nPlease enter a valid binary number!");
	}
	return 0;
}

thnx