hex2dec.c

/*
 * hex2dec.cxx
 *
 * Copyright 2018 Денис <altracer@AspireE15>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 *
 *
 */

#include <iostream>
#include <math.h>
#include <locale.h>
using namespace std;

int main(int argc, char **argv)
{
    setlocale(LC_ALL,"RUS");
    short l = 2;
    char a[l+1]; // last symbol is line terminator '\0'
    short b = 0;
    short i,j;
    cout << "Введите шестнадцатеричное число от 00h до FFh (без h):" << endl;
    cin >> a;

    const char hex_alphabet[17] = "0123456789ABCDEF";
    int dec_alphabet[16];
    for(i=0;i<=15;i++) dec_alphabet[i]=i;

    for(i=0;i<=l-1;i++){
        for(j=0;j<=15;j++){
            if(a[l-1-i]==hex_alphabet[j]) b+=dec_alphabet[j]*pow(16,i);
        };
    };

    cout << b <<endl;
    return 0;
}