write a c program to convert a given number into binary and a binary number to decimal

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

int convert(long n);
long convert_decimal_to_binary(int n);
main()
{
    int dec;
    long n;
    printf("Enter a binary number: ");
    scanf("%lld", &n);
    printf("%lld in binary = %d in decimaln", n, convert_binary_to_decimal(n));
    dec=convert_binary_to_decimal(n);
    printf("%d in decimal = %lld in binaryn", dec, convert_decimal_to_binary(dec));

}

int convert_binary_to_decimal(long n)
{
    int dec = 0, i = 0, rem;
    while (n != 0)
    {
        rem = n % 10;
        n /= 10;
        dec += rem * pow(2, i);
        ++i;
    }
    return dec;
}
long convert_decimal_to_binary(int n)
{
    long long bin = 0;
    int rem, i = 1;
    while (n != 0)
    {
        rem = n % 2;
        n /= 2;
        bin += rem * i;
        i *= 10;
    }
    return bin;
}