codice:
#include <stdio.h> // printf()
#include <stdlib.h> // system()
#include <string.h> // strlen()
#include <math.h> // pow()

int main()
{
    char bin[] = "01000100";
    unsigned int len, exp = 0, dec = 0, hex = 0;
    
    
    // da BIN a DEC
    
    len = strlen(bin) - 1;
                      
    while (1)
    {
	if(bin[len] == '1')
            dec = dec + pow(2, exp);
    	         
        exp++;
        if(len == 0) break;
        len--;
         
    }
   
    printf("DEC = %d\n", dec);
    
    // da DEC a BIN
    
    itoa(dec, bin, 2);
    
    printf("BIN = %s\n", bin);
    
    // da DEC a HEX
    
    itoa(dec, bin, 16);
    hex = atoi(bin);
    
    printf("HEX = %d\n", hex);
        
    system("pause");
    return 0;
}