C programming, Transform binary numbers into decimal format and convert them back to binary.

#include <stdio.h>

long long convert(long long);

int main() {

    long long n;

    printf("Enter a binary number: ");

    scanf("%lld", &n);

    printf("%lld in binary = %lld in decimal", n, convert(n));

    return 0;

}

long long convert(long long n) {

    long long dec = 0;

    int i = 0, rem;

    while (n != 0) {

        rem = n % 10;

        dec += rem << i; // Using bitwise shift instead of pow

        n /= 10;

        ++i;

    }

    return dec;

}