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05780f4b MM |
1 | /* |
2 | * Matt McCutchen's Big Integer Library | |
3 | * http://mysite.verizon.net/mccutchen/bigint/ | |
4 | */ | |
5 | ||
6 | #ifndef BIGINTEGERUTILS | |
7 | #define BIGINTEGERUTILS | |
8 | ||
9 | #include "BigInteger.hh" | |
10 | #include <string> | |
11 | #include <iostream> | |
12 | ||
13 | /* | |
14 | * This file includes: | |
15 | * (1) `std::string <=> BigUnsigned/BigInteger' conversion routines easier than `BigUnsignedInABase' | |
16 | * (2) << and >> operators for BigUnsigned/BigInteger, std::istream/std::ostream | |
17 | */ | |
18 | ||
19 | // Conversion routines. Base 10 only. | |
20 | std::string easyBUtoString(const BigUnsigned &x); | |
21 | std::string easyBItoString(const BigInteger &x); | |
22 | BigUnsigned easyStringToBU(const std::string &s); | |
23 | BigInteger easyStringToBI(const std::string &s); | |
24 | ||
a8b42b68 MM |
25 | // Creates a BigInteger from data such as `char's; read below for details. |
26 | template <class T> | |
27 | BigInteger easyDataToBI(const T* data, BigInteger::Index length, BigInteger::Sign sign); | |
28 | ||
05780f4b MM |
29 | // Outputs x to os, obeying the flags `dec', `hex', `bin', and `showbase'. |
30 | std::ostream &operator <<(std::ostream &os, const BigUnsigned &x); | |
31 | ||
32 | // Outputs x to os, obeying the flags `dec', `hex', `bin', and `showbase'. | |
33 | // My somewhat arbitrary policy: a negative sign comes before a base indicator (like -0xFF). | |
34 | std::ostream &operator <<(std::ostream &os, const BigInteger &x); | |
35 | ||
a8b42b68 MM |
36 | /* |
37 | * ================================= | |
38 | * BELOW THIS POINT are template definitions; above are declarations. See `NumberlikeArray.hh'. | |
39 | */ | |
40 | ||
41 | /* | |
42 | * Converts binary data to a BigInteger. | |
43 | * Pass an array `data', its length, and the desired sign. | |
44 | * | |
45 | * Elements of `data' may be of any type `T' that has the following | |
46 | * two properties (this includes almost all integral types): | |
47 | * | |
48 | * (1) `sizeof(T)' correctly gives the amount of binary data in one | |
49 | * value of `T' and is a factor of `sizeof(Blk)'. | |
50 | * | |
51 | * (2) When a value of `T' is casted to a `Blk', the low bytes of | |
52 | * the result contain the desired binary data. | |
53 | */ | |
54 | template <class T> | |
55 | BigInteger easyDataToBI(const T* data, BigInteger::Index length, BigInteger::Sign sign) { | |
56 | // really ceiling(numBytes / sizeof(BigInteger::Blk)) | |
57 | unsigned int pieceSizeInBits = 8 * sizeof(T); | |
58 | unsigned int piecesPerBlock = sizeof(BigInteger::Blk) / sizeof(T); | |
59 | unsigned int numBlocks = (length + piecesPerBlock - 1) / piecesPerBlock; | |
60 | std::cout << pieceSizeInBits << ' ' << piecesPerBlock << ' ' << numBlocks << std::endl; | |
61 | ||
62 | // Allocate our block array | |
63 | BigInteger::Blk *blocks = new BigInteger::Blk[numBlocks]; | |
64 | ||
65 | BigInteger::Index blockNum, pieceNum, pieceNumHere; | |
66 | ||
67 | // Convert | |
68 | for (BigInteger::Index blockNum = 0, pieceNum = 0; blockNum < numBlocks; blockNum++) { | |
69 | BigInteger::Blk curBlock = 0; | |
70 | for (unsigned int pieceNumHere = 0; pieceNumHere < piecesPerBlock && pieceNum < length; | |
71 | pieceNumHere++, pieceNum++) | |
72 | curBlock |= (BigInteger::Blk(data[pieceNum]) << (pieceSizeInBits * pieceNumHere)); | |
73 | blocks[blockNum] = curBlock; | |
74 | std::cout << curBlock << std::endl; | |
75 | } | |
76 | ||
77 | // Create the BigInteger. | |
78 | BigInteger x(blocks, numBlocks, sign); | |
79 | ||
80 | delete blocks; | |
81 | return x; | |
82 | } | |
83 | ||
05780f4b | 84 | #endif |