C_CPP/02_MENT/main_02_MENT.cpp

// file: main_02_MENT.cpp
// THIS IS C++, use clang++

#include <iostream>

#include "../helpers/println.hpp"

struct PascalString{
	int length;            // number of chars used
	char characters[256];  // chars of some character string
};

int hexDigitToInt(char hexDigit) {
int value = 0;

if(hexDigit > 47 && hexDigit < 58)
    value = hexDigit - 48;

if(hexDigit > 96 && hexDigit < 103)
    value = hexDigit - 97 + 10;

return value;
}

int hexStringToInt(PascalString binaryDigits) {
    int returnValue = 0;

    for(int i = 0; i <= binaryDigits.length; ++i) {
        returnValue += binaryDigits.characters[i];
    }

    return returnValue;
}



void printPascalString(PascalString s) {
    for(int i = 0; i <= s.length; i++) {
        println(s.characters[i]);
    }
}

PascalString intToDual(int n) {
    
    int i = std::to_string(n).length() * 4;
    PascalString string = {i};
    while(n >= 1) {
        string.characters[i] = (n % 2) + '0';
        n = n / 2;
        i--;
    }
    
    
    return string;
}

int main(int argc, char** argv, char** envp) {

  PascalString s = {3, '1', '0', '0'};
  PascalString s2 = {4, 'f', 'f', 'f', 'f'};
  println(hexStringToInt(s));
  println(hexStringToInt(s2));

  println(hexDigitToInt('d'));
  println(hexDigitToInt('9'));
  println(hexDigitToInt('2'));
  
  printPascalString(s2);
  
  int controlRegister = 128;
  controlRegister |= 64+32;
  controlRegister ^=16;
  controlRegister &= 128+64;
  controlRegister <<= 1;
  
  println(controlRegister);
  
  printPascalString(intToDual(41));
  
  return 0;
}