// largeint.h (Declaration of Class LargeInt)

#include <vector>
#include <string>


class LargeInt {
public:
    using inputtype = long long;

    LargeInt(inputtype);                           // constructor
    std::string decimal() const;                   // decimal representation
    bool operator<(const LargeInt &) const;        // comparison
    LargeInt operator+(const LargeInt &) const;    // addition
    const LargeInt & operator+=(const LargeInt &); // addition

private:
    std::vector<short> _v;  // store single digits, last digit in _v[0]
    static const std::string digits;
};