// A1Q2.cpp
#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;

int main()
{
	char compactedS[12];
	int compactedV[3]={0,0,0};
	int hexNumber[12];
	int asc2[8];
	short i=0,j=0,temp=1;

	cout << "Please enter the compacted string of bits in Hexadecimal format: ";
	cin >> compactedS;  // get input compacted values as Char;
	
	for(i=0;i<3;i++)
		{
			for(j=0;j<4;j++)
				{
					if (compactedS[i*4+j]>=97 && compactedS[i*4+j]<=102)
						hexNumber[i*4+j] = compactedS[i*4+j] -87;
					else if  (compactedS[i*4+j]>=65 && compactedS[i*4+j]<=70)
						hexNumber[i*4+j] = compactedS[i*4+j] -55;
					else if  (compactedS[i*4+j]>=48 && compactedS[i*4+j]<=57)
						hexNumber[i*4+j] = compactedS[i*4+j] -48;
					else 
						temp = 0; //input invalid characters, change temp to 0;

					compactedV[i] = compactedV[i] + hexNumber[i*4+j] * (int)pow(16,3-j); // trasfer char to integer value;
				}
		}

	for(i=0;i<8;i++)
		{		
			asc2[i]=compactedV[i/3]-compactedV[i/3]/40*40;
			compactedV[i/3]=(compactedV[i/3]-asc2[i])/40; // converting compacted values back to number from 1 to 36;
		}

	for(i=0;i<8;i++)
		{
			if (asc2[i]>=27 && asc2[i]<=36)
				asc2[i]=asc2[i]+21; //convert '0' to '9' to ASCII code.
			else if (asc2[i]>=1 && asc2[i]<=26)
				asc2[i]=asc2[i]+64; //convert 'A' to 'Z' to ASCII code.
			else 
				temp=0;
		}

	if (temp!=0)
		{
			cout << "The original user id in ASCII format is "; 
			for(i=0;i<8;i++)
				cout << hex << uppercase << asc2[i] << "  "; // output
			cout << "\n" ;
			cout << "(" ;
			for(i=0;i<8;i++)
				cout << (char)asc2[i];
			cout << ")\n" << endl;
		}
	else 
			cout << "You input invalid character." << endl;

	return 0;
}