#include <string>
#include <cstring>
#include <iostream>
#include <iomanip>
 
using namespace std;
 
const char digs[] = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
 
unsigned long long code62(const string& ss)
{
    unsigned long long code = 0;
    for(const char * s = ss.c_str(); *s; ++s)
    {
        code = code * 62 + (strchr(digs,*s)-digs); // Номер символа
    }
    return code;
}
 
string decode62(unsigned long long val)
{
    string res;
    while(val)
    {
        res = digs[val%62] + res;
        val /= 62;
    }
    return res;
}
 
 
int main(int argc, const char * argv[])
{
    unsigned long long code = code62("BOOzE");
    cout << code << endl;
    cout << decode62(code) << endl;
}
 

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