-/*
-* Matt McCutchen's Big Integer Library
-* http://mysite.verizon.net/mccutchen/bigint/
-*/
-
#include "BigUnsignedInABase.hh"
+BigUnsignedInABase::BigUnsignedInABase(const Digit *d, Index l, Base base)
+ : NumberlikeArray<Digit>(d, l), base(base) {
+ // Check the base
+ if (base < 2)
+ throw "BigUnsignedInABase::BigUnsignedInABase(const Digit *, Index, Base): The base must be at least 2";
+
+ // Validate the digits.
+ for (Index i = 0; i < l; i++)
+ if (blk[i] >= base)
+ throw "BigUnsignedInABase::BigUnsignedInABase(const Digit *, Index, Base): A digit is too large for the specified base";
+
+ // Eliminate any leading zeros we may have been passed.
+ zapLeadingZeros();
+}
+
namespace {
unsigned int bitLen(unsigned int x) {
unsigned int len = 0;
// Check the base
if (base < 2)
throw "BigUnsignedInABase(BigUnsigned, Base): The base must be at least 2";
- // Save the base.
- // This pattern is seldom seen in C++, but the analogous ``this.'' is common in Java.
this->base = base;
-
+
// Get an upper bound on how much space we need
- int maxBitLenOfX = x.getLength() * 8 * sizeof(BigUnsigned::Blk);
+ int maxBitLenOfX = x.getLength() * BigUnsigned::N;
int minBitsPerDigit = bitLen(base) - 1;
int maxDigitLenOfX = ceilingDiv(maxBitLenOfX, minBitsPerDigit);
- allocate(maxDigitLenOfX); // Get the space
-
+ len = maxDigitLenOfX; // Another change to comply with `staying in bounds'.
+ allocate(len); // Get the space
+
BigUnsigned x2(x), buBase(base);
Index digitNum = 0;
-
+
while (!x2.isZero()) {
// Get last digit. This is like `lastDigit = x2 % buBase, x2 /= buBase'.
BigUnsigned lastDigit(x2);
lastDigit.divideWithRemainder(buBase, x2);
// Save the digit.
- blk[digitNum] = Digit(lastDigit); // invokes `BigUnsigned ==> unsigned short' converter
+ blk[digitNum] = lastDigit.toUnsignedShort();
// Move on. We can't run out of room: we figured it out above.
digitNum++;
}
-
- // Save the eventual length.
+
+ // Save the actual length.
len = digitNum;
}
// Save the base.
// This pattern is seldom seen in C++, but the analogous ``this.'' is common in Java.
this->base = base;
-
- len = s.length();
+
+ // `s.length()' is a `size_t', while `len' is a `NumberlikeArray::Index',
+ // also known as an `unsigned int'. Some compilers warn without this cast.
+ len = Index(s.length());
allocate(len);
-
+
Index digitNum, symbolNumInString;
for (digitNum = 0; digitNum < len; digitNum++) {
symbolNumInString = len - 1 - digitNum;
throw "BigUnsignedInABase ==> std::string: The default string conversion routines use the symbol set 0-9, A-Z and therefore support only up to base 36. You tried a conversion with a base over 36; write your own string conversion routine.";
if (len == 0)
return std::string("0");
- std::string s;
- s.reserve(len);
+ // Some compilers don't have push_back, so use a char * buffer instead.
+ char *s = new char[len + 1];
+ s[len] = '\0';
Index digitNum, symbolNumInString;
for (symbolNumInString = 0; symbolNumInString < len; symbolNumInString++) {
digitNum = len - 1 - symbolNumInString;
Digit theDigit = blk[digitNum];
if (theDigit < 10)
- s.push_back(char('0' + theDigit));
+ s[symbolNumInString] = char('0' + theDigit);
else
- s.push_back(char('A' + theDigit - 10));
+ s[symbolNumInString] = char('A' + theDigit - 10);
}
- return s;
+ std::string s2(s);
+ delete [] s;
+ return s2;
}