Binary to Decimal C Program

The formula of Binary to Decimal is:

Decimal Number = (n^th digit of binary number) * 2^(n-1) + ((n-1)^th digit of binary number) * 2^(n-2) + …… + (1^st digit of binary number) * 2⁽⁰⁾

Suppose 1101 is the binary number. Then the decimal number will be:

Decimal Number = (1 * 2³ + 1 * 2² + 0 * 2¹ + 1* 2⁰) = (8 + 4 + 0 + 1) = 13

Here is the C program to convert Binary Number into Decimal Number:

#include <stdio.h>
#include <math.h>

int main()
{
    int binary, decimal = 0, i, j=0;
    printf("Enter a binary number: ");
    scanf("%d",&binary);
    int temp;
    temp = binary;
    if(temp>0){
        i = temp % 10;
        if(i==0 || i==1){
            while(temp!=0){
                i = temp % 10;
                decimal = decimal + i * pow(2, j);
                temp = temp / 10;
                j++;
            }
        }
    }
    if(decimal==0 || binary<0)
        printf("The number is not a binary number !");
    else printf("The equivalent decimal number of %d is : %d.",binary,decimal);
    return 0;
}

NB: Here pow(x,y) is a function that comes with header file math.h. It returns x to the power y.
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