/* Due date for this lab: Saturday 11/5 */ 
/* Please email me your code using the following command  */
/* mail -s "CISC2100 lab2" xzhang@fordham.edu < hash.cpp */
#include <iostream>
#include <string>
#include <stdio.h>
#include <math.h>
using namespace std;

/* Calculate the digits of the given num in the given base. 
 * precondition: num>=0 
 * postcondition: return an array of digits, digit[0] is the zero-th digit (rightmost),
 *   digit[1] is the second to the right... 
 *   digitsLen stores the length of the array 
 */
/*  Todo by you:  Modify this function so that it can convert/calculate
 *  the digits of num in other base */ 
int * ConvertToBase2 (unsigned int num, int & digitsLen)
{
   
   //Step 1: Decide how many binary digits are needed... (Using logarithm). 
   //  use command "man" to find out how to use math functions (log, log2...) 
   //   e.g., man log2
   digitsLen = (int)(log2(num))+1;

   // Step 2: allocate int array dynamically of the given length 
   int * digits = new int[digitsLen];
   
   // Step 3: 
   for (int i=0;i<digitsLen;i++)
   {
	digits[i] = num%2;
	num = num/2;
   }
   return digits;
}

/* parse the input string and convert it to the corresponding number
 * e.g., if input is "1256" base is 10, then the function return 1256
 *       if input is "101", base is 2, then the function returns 5
 *       if input is "11", base is 8, it returns 9.
 *  Note: you can convert the ascii code for a digit (such as '5') to 
 *    the value of the digit (such as int 5) by substracting '0' from the ascii code
 *    '5'-'0' is 5
 *    '9'-'0' is 9 
 *    You can assume that the input is valid. 
 */ 
int ConvertStringToInt (string input, int base)
{
   //todo by you
}


int main()
{
   int input;
   char sel;
   string inputString;
   int base;
   int * digits; 
   int len;

   cout <<"First convert base 10 to other base\n";
   do {
     cout <<"Enter a number:";
     cin >> input;
	
     //Test your functions above 
     digits = ConvertToBase2 (input, len);

     cout <<"The binary representation is: ";
     for (int i=len-1;i>=0;i--)
	cout <<digits[i];
     cout <<endl;

     cout <<"\nCont(y/n)?";
     cin >> sel;
   } while (sel=='y' || sel=='Y');


   cout <<"now convert other base to base 10 \n";
  //  base 2 or 8 to base 10 
   do { 
     cout <<"Enter a number, and then its base";
     cin >> inputString >> base;

    //Call ConvertStringToInt function here... 


     cout <<"\nCont(y/n)?";
     cin >> sel;

   } while (sel=='y' || sel=='Y');
}