HEX to DEC

#include <iostream>

using std::cout;
using std::cin;
using std::endl;

void main()
{
    setlocale(LC_ALL, "Russian");
    const int size = 16;
    long long int power[size], pow = 1;
    long long int dec = 0;

    char hex[size] = {};
    cout << "Введите шестнадцатиричное число -> "; cin >> hex;

    for (int i = 0; i < size; i++)
    {
        power[i] = pow;
        pow *= 16;
    }

    int i = 0;

    for (int i = 0; i < size; ((hex[i] == 'A') ? hex[i] = (int)10 : (hex[i] == 'B') ? hex[i] = (int)11 : (hex[i] == 'C') ? hex[i] = (int)12 : (hex[i] == 'D') ? hex[i] = (int)13 :
                               (hex[i] == 'E') ? hex[i] = (int)14 : (hex[i] == 'F') ? hex[i] = (int)15 : /* (hex[i] <= 0) ? hex[i] *= (int)0 : */ hex[i] = (char)hex[i] - 48), i++);

    for (int i = size - 1, j = 0; i >= 0; i--)
    {
        if (hex[i] >= 0) dec = dec + ((int)hex[i] * power[j++]);
    }

    cout << "Десятичное число: " << dec << endl;
}