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

int binaryToDecimal(int num)
{
    int decimal = 0, i = 0, remainder;
    while (num != 0)
    {
        remainder = num % 10;
        num /= 10;
        decimal += remainder * pow(2, i);
        ++i;
    }

    return decimal;
}

long long int decimalToBinary(long long int n)
{
    long long int binary = 0;
    int rem, i = 1, step = 1;

    while (n != 0)
    {
        rem = n % 2;
        n /= 2;
        binary += rem * i;
        i *= 10;
    }

    return binary;
}

int main()
{
    int operation, decimal;
    long long int binary;
    printf("-----Select the Operation------\n");
    printf("1. Binary to Decimal\n2. Decimal to Binary\n3. Exit\n");
    printf("Enter the corresponding number of Operation: ");
    scanf("%d", &operation);

    switch (operation)
    {
    case 1:
        printf("Enter the Binary Number: ");
        scanf("%lld", &binary);
        printf("%d in decimal", binaryToDecimal(binary));
        break;

    case 2:
        printf("Enter the Decimal Number: ");
        scanf("%d", &decimal);
        printf("%lld in binary", decimalToBinary(decimal));
        break;

    case 3:
        exit(0);

    default:
        printf("Wrong input");
    }

    return 0;
}