| 1 | /* |
| 2 | * Matt McCutchen's Big Integer Library |
| 3 | * http://mysite.verizon.net/mccutchen/bigint/ |
| 4 | */ |
| 5 | |
| 6 | #include "BigIntegerUtils.hh" |
| 7 | #include "BigUnsignedInABase.hh" |
| 8 | |
| 9 | /* |
| 10 | * This file includes: |
| 11 | * (1) `std::string <=> BigUnsigned/BigInteger' conversion routines easier than `BigUnsignedInABase' |
| 12 | * (2) << and >> operators for BigUnsigned/BigInteger, std::istream/std::ostream |
| 13 | */ |
| 14 | |
| 15 | std::string easyBUtoString(const BigUnsigned &x) { |
| 16 | return std::string(BigUnsignedInABase(x, 10)); |
| 17 | } |
| 18 | |
| 19 | std::string easyBItoString(const BigInteger &x) { |
| 20 | return (x.getSign() == BigInteger::negative) ? |
| 21 | (std::string("-") + easyBUtoString(x)) : (easyBUtoString(x)); |
| 22 | } |
| 23 | |
| 24 | BigUnsigned easyStringToBU(const std::string &s) { |
| 25 | return BigUnsigned(BigUnsignedInABase(s, 10)); |
| 26 | } |
| 27 | |
| 28 | BigInteger easyStringToBI(const std::string &s) { |
| 29 | return (s[0] == '-') ? |
| 30 | BigInteger(easyStringToBU(s.substr(1, s.length() - 1)), BigInteger::negative) : |
| 31 | BigInteger(easyStringToBU(s)); |
| 32 | } |
| 33 | |
| 34 | // Outputs x to os, obeying the flags `dec', `hex', `bin', and `showbase'. |
| 35 | std::ostream &operator <<(std::ostream &os, const BigUnsigned &x) { |
| 36 | BigUnsignedInABase::Base base; |
| 37 | long osFlags = os.flags(); |
| 38 | if (osFlags & os.dec) |
| 39 | base = 10; |
| 40 | else if (osFlags & os.hex) { |
| 41 | base = 16; |
| 42 | if (osFlags & os.showbase) |
| 43 | os << "0x"; |
| 44 | } else if (osFlags & os.oct) { |
| 45 | base = 8; |
| 46 | if (osFlags & os.showbase) |
| 47 | os << '0'; |
| 48 | } else |
| 49 | throw "std::ostream << BigUnsigned: Could not determine the desired base from output-stream flags"; |
| 50 | std::string s = std::string(BigUnsignedInABase(x, base)); |
| 51 | os << s; |
| 52 | return os; |
| 53 | } |
| 54 | // Outputs x to os, obeying the flags `dec', `hex', `bin', and `showbase'. |
| 55 | // My somewhat arbitrary policy: a negative sign comes before a base indicator (like -0xFF). |
| 56 | std::ostream &operator <<(std::ostream &os, const BigInteger &x) { |
| 57 | if (x.getSign() == BigInteger::negative) |
| 58 | os << '-'; |
| 59 | os << (const BigUnsigned &)(x); |
| 60 | return os; |
| 61 | } |