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1 | package Math::BigInt; |
2 | |
3 | %OVERLOAD = ( |
4 | # Anonymous subroutines: |
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5 | '+' => sub {new Math::BigInt &badd}, |
6 | '-' => sub {new Math::BigInt |
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7 | $_[2]? bsub($_[1],${$_[0]}) : bsub(${$_[0]},$_[1])}, |
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8 | '<=>' => sub {new Math::BigInt |
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9 | $_[2]? bcmp($_[1],${$_[0]}) : bcmp(${$_[0]},$_[1])}, |
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10 | 'cmp' => sub {new Math::BigInt |
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11 | $_[2]? ($_[1] cmp ${$_[0]}) : (${$_[0]} cmp $_[1])}, |
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12 | '*' => sub {new Math::BigInt &bmul}, |
13 | '/' => sub {new Math::BigInt |
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14 | $_[2]? scalar bdiv($_[1],${$_[0]}) : |
15 | scalar bdiv(${$_[0]},$_[1])}, |
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16 | '%' => sub {new Math::BigInt |
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17 | $_[2]? bmod($_[1],${$_[0]}) : bmod(${$_[0]},$_[1])}, |
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18 | '**' => sub {new Math::BigInt |
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19 | $_[2]? bpow($_[1],${$_[0]}) : bpow(${$_[0]},$_[1])}, |
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20 | 'neg' => sub {new Math::BigInt &bneg}, |
21 | 'abs' => sub {new Math::BigInt &babs}, |
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22 | |
23 | qw( |
24 | "" stringify |
25 | 0+ numify) # Order of arguments unsignificant |
26 | ); |
27 | |
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28 | $NaNOK=1; |
29 | |
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30 | sub new { |
31 | my $foo = bnorm($_[1]); |
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32 | die "Not a number initialized to Math::BigInt" if !$NaNOK && $foo eq "NaN"; |
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33 | bless \$foo; |
34 | } |
35 | sub stringify { "${$_[0]}" } |
36 | sub numify { 0 + "${$_[0]}" } # Not needed, additional overhead |
37 | # comparing to direct compilation based on |
38 | # stringify |
39 | |
40 | # arbitrary size integer math package |
41 | # |
42 | # by Mark Biggar |
43 | # |
44 | # Canonical Big integer value are strings of the form |
45 | # /^[+-]\d+$/ with leading zeros suppressed |
46 | # Input values to these routines may be strings of the form |
47 | # /^\s*[+-]?[\d\s]+$/. |
48 | # Examples: |
49 | # '+0' canonical zero value |
50 | # ' -123 123 123' canonical value '-123123123' |
51 | # '1 23 456 7890' canonical value '+1234567890' |
52 | # Output values always always in canonical form |
53 | # |
54 | # Actual math is done in an internal format consisting of an array |
55 | # whose first element is the sign (/^[+-]$/) and whose remaining |
56 | # elements are base 100000 digits with the least significant digit first. |
57 | # The string 'NaN' is used to represent the result when input arguments |
58 | # are not numbers, as well as the result of dividing by zero |
59 | # |
60 | # routines provided are: |
61 | # |
62 | # bneg(BINT) return BINT negation |
63 | # babs(BINT) return BINT absolute value |
64 | # bcmp(BINT,BINT) return CODE compare numbers (undef,<0,=0,>0) |
65 | # badd(BINT,BINT) return BINT addition |
66 | # bsub(BINT,BINT) return BINT subtraction |
67 | # bmul(BINT,BINT) return BINT multiplication |
68 | # bdiv(BINT,BINT) return (BINT,BINT) division (quo,rem) just quo if scalar |
69 | # bmod(BINT,BINT) return BINT modulus |
70 | # bgcd(BINT,BINT) return BINT greatest common divisor |
71 | # bnorm(BINT) return BINT normalization |
72 | # |
73 | |
74 | $zero = 0; |
75 | |
76 | \f |
77 | # normalize string form of number. Strip leading zeros. Strip any |
78 | # white space and add a sign, if missing. |
79 | # Strings that are not numbers result the value 'NaN'. |
80 | |
81 | sub bnorm { #(num_str) return num_str |
82 | local($_) = @_; |
83 | s/\s+//g; # strip white space |
84 | if (s/^([+-]?)0*(\d+)$/$1$2/) { # test if number |
85 | substr($_,$[,0) = '+' unless $1; # Add missing sign |
86 | s/^-0/+0/; |
87 | $_; |
88 | } else { |
89 | 'NaN'; |
90 | } |
91 | } |
92 | |
93 | # Convert a number from string format to internal base 100000 format. |
94 | # Assumes normalized value as input. |
95 | sub internal { #(num_str) return int_num_array |
96 | local($d) = @_; |
97 | ($is,$il) = (substr($d,$[,1),length($d)-2); |
98 | substr($d,$[,1) = ''; |
99 | ($is, reverse(unpack("a" . ($il%5+1) . ("a5" x ($il/5)), $d))); |
100 | } |
101 | |
102 | # Convert a number from internal base 100000 format to string format. |
103 | # This routine scribbles all over input array. |
104 | sub external { #(int_num_array) return num_str |
105 | $es = shift; |
106 | grep($_ > 9999 || ($_ = substr('0000'.$_,-5)), @_); # zero pad |
107 | &bnorm(join('', $es, reverse(@_))); # reverse concat and normalize |
108 | } |
109 | |
110 | # Negate input value. |
111 | sub bneg { #(num_str) return num_str |
112 | local($_) = &bnorm(@_); |
113 | vec($_,0,8) ^= ord('+') ^ ord('-') unless $_ eq '+0'; |
114 | s/^H/N/; |
115 | $_; |
116 | } |
117 | |
118 | # Returns the absolute value of the input. |
119 | sub babs { #(num_str) return num_str |
120 | &abs(&bnorm(@_)); |
121 | } |
122 | |
123 | sub abs { # post-normalized abs for internal use |
124 | local($_) = @_; |
125 | s/^-/+/; |
126 | $_; |
127 | } |
128 | \f |
129 | # Compares 2 values. Returns one of undef, <0, =0, >0. (suitable for sort) |
130 | sub bcmp { #(num_str, num_str) return cond_code |
131 | local($x,$y) = (&bnorm($_[$[]),&bnorm($_[$[+1])); |
132 | if ($x eq 'NaN') { |
133 | undef; |
134 | } elsif ($y eq 'NaN') { |
135 | undef; |
136 | } else { |
137 | &cmp($x,$y); |
138 | } |
139 | } |
140 | |
141 | sub cmp { # post-normalized compare for internal use |
142 | local($cx, $cy) = @_; |
143 | $cx cmp $cy |
144 | && |
145 | ( |
146 | ord($cy) <=> ord($cx) |
147 | || |
148 | ($cx cmp ',') * (length($cy) <=> length($cx) || $cy cmp $cx) |
149 | ); |
150 | } |
151 | |
152 | sub badd { #(num_str, num_str) return num_str |
153 | local(*x, *y); ($x, $y) = (&bnorm($_[$[]),&bnorm($_[$[+1])); |
154 | if ($x eq 'NaN') { |
155 | 'NaN'; |
156 | } elsif ($y eq 'NaN') { |
157 | 'NaN'; |
158 | } else { |
159 | @x = &internal($x); # convert to internal form |
160 | @y = &internal($y); |
161 | local($sx, $sy) = (shift @x, shift @y); # get signs |
162 | if ($sx eq $sy) { |
163 | &external($sx, &add(*x, *y)); # if same sign add |
164 | } else { |
165 | ($x, $y) = (&abs($x),&abs($y)); # make abs |
166 | if (&cmp($y,$x) > 0) { |
167 | &external($sy, &sub(*y, *x)); |
168 | } else { |
169 | &external($sx, &sub(*x, *y)); |
170 | } |
171 | } |
172 | } |
173 | } |
174 | |
175 | sub bsub { #(num_str, num_str) return num_str |
176 | &badd($_[$[],&bneg($_[$[+1])); |
177 | } |
178 | |
179 | # GCD -- Euclids algorithm Knuth Vol 2 pg 296 |
180 | sub bgcd { #(num_str, num_str) return num_str |
181 | local($x,$y) = (&bnorm($_[$[]),&bnorm($_[$[+1])); |
182 | if ($x eq 'NaN' || $y eq 'NaN') { |
183 | 'NaN'; |
184 | } else { |
185 | ($x, $y) = ($y,&bmod($x,$y)) while $y ne '+0'; |
186 | $x; |
187 | } |
188 | } |
189 | \f |
190 | # routine to add two base 1e5 numbers |
191 | # stolen from Knuth Vol 2 Algorithm A pg 231 |
192 | # there are separate routines to add and sub as per Kunth pg 233 |
193 | sub add { #(int_num_array, int_num_array) return int_num_array |
194 | local(*x, *y) = @_; |
195 | $car = 0; |
196 | for $x (@x) { |
197 | last unless @y || $car; |
198 | $x -= 1e5 if $car = (($x += shift(@y) + $car) >= 1e5); |
199 | } |
200 | for $y (@y) { |
201 | last unless $car; |
202 | $y -= 1e5 if $car = (($y += $car) >= 1e5); |
203 | } |
204 | (@x, @y, $car); |
205 | } |
206 | |
207 | # subtract base 1e5 numbers -- stolen from Knuth Vol 2 pg 232, $x > $y |
208 | sub sub { #(int_num_array, int_num_array) return int_num_array |
209 | local(*sx, *sy) = @_; |
210 | $bar = 0; |
211 | for $sx (@sx) { |
212 | last unless @y || $bar; |
213 | $sx += 1e5 if $bar = (($sx -= shift(@sy) + $bar) < 0); |
214 | } |
215 | @sx; |
216 | } |
217 | |
218 | # multiply two numbers -- stolen from Knuth Vol 2 pg 233 |
219 | sub bmul { #(num_str, num_str) return num_str |
220 | local(*x, *y); ($x, $y) = (&bnorm($_[$[]), &bnorm($_[$[+1])); |
221 | if ($x eq 'NaN') { |
222 | 'NaN'; |
223 | } elsif ($y eq 'NaN') { |
224 | 'NaN'; |
225 | } else { |
226 | @x = &internal($x); |
227 | @y = &internal($y); |
228 | &external(&mul(*x,*y)); |
229 | } |
230 | } |
231 | |
232 | # multiply two numbers in internal representation |
233 | # destroys the arguments, supposes that two arguments are different |
234 | sub mul { #(*int_num_array, *int_num_array) return int_num_array |
235 | local(*x, *y) = (shift, shift); |
236 | local($signr) = (shift @x ne shift @y) ? '-' : '+'; |
237 | @prod = (); |
238 | for $x (@x) { |
239 | ($car, $cty) = (0, $[); |
240 | for $y (@y) { |
241 | $prod = $x * $y + $prod[$cty] + $car; |
242 | $prod[$cty++] = |
243 | $prod - ($car = int($prod * 1e-5)) * 1e5; |
244 | } |
245 | $prod[$cty] += $car if $car; |
246 | $x = shift @prod; |
247 | } |
248 | ($signr, @x, @prod); |
249 | } |
250 | |
251 | # modulus |
252 | sub bmod { #(num_str, num_str) return num_str |
253 | (&bdiv(@_))[$[+1]; |
254 | } |
255 | \f |
256 | sub bdiv { #(dividend: num_str, divisor: num_str) return num_str |
257 | local (*x, *y); ($x, $y) = (&bnorm($_[$[]), &bnorm($_[$[+1])); |
258 | return wantarray ? ('NaN','NaN') : 'NaN' |
259 | if ($x eq 'NaN' || $y eq 'NaN' || $y eq '+0'); |
260 | return wantarray ? ('+0',$x) : '+0' if (&cmp(&abs($x),&abs($y)) < 0); |
261 | @x = &internal($x); @y = &internal($y); |
262 | $srem = $y[$[]; |
263 | $sr = (shift @x ne shift @y) ? '-' : '+'; |
264 | $car = $bar = $prd = 0; |
265 | if (($dd = int(1e5/($y[$#y]+1))) != 1) { |
266 | for $x (@x) { |
267 | $x = $x * $dd + $car; |
268 | $x -= ($car = int($x * 1e-5)) * 1e5; |
269 | } |
270 | push(@x, $car); $car = 0; |
271 | for $y (@y) { |
272 | $y = $y * $dd + $car; |
273 | $y -= ($car = int($y * 1e-5)) * 1e5; |
274 | } |
275 | } |
276 | else { |
277 | push(@x, 0); |
278 | } |
279 | @q = (); ($v2,$v1) = @y[-2,-1]; |
280 | while ($#x > $#y) { |
281 | ($u2,$u1,$u0) = @x[-3..-1]; |
282 | $q = (($u0 == $v1) ? 99999 : int(($u0*1e5+$u1)/$v1)); |
283 | --$q while ($v2*$q > ($u0*1e5+$u1-$q*$v1)*1e5+$u2); |
284 | if ($q) { |
285 | ($car, $bar) = (0,0); |
286 | for ($y = $[, $x = $#x-$#y+$[-1; $y <= $#y; ++$y,++$x) { |
287 | $prd = $q * $y[$y] + $car; |
288 | $prd -= ($car = int($prd * 1e-5)) * 1e5; |
289 | $x[$x] += 1e5 if ($bar = (($x[$x] -= $prd + $bar) < 0)); |
290 | } |
291 | if ($x[$#x] < $car + $bar) { |
292 | $car = 0; --$q; |
293 | for ($y = $[, $x = $#x-$#y+$[-1; $y <= $#y; ++$y,++$x) { |
294 | $x[$x] -= 1e5 |
295 | if ($car = (($x[$x] += $y[$y] + $car) > 1e5)); |
296 | } |
297 | } |
298 | } |
299 | pop(@x); unshift(@q, $q); |
300 | } |
301 | if (wantarray) { |
302 | @d = (); |
303 | if ($dd != 1) { |
304 | $car = 0; |
305 | for $x (reverse @x) { |
306 | $prd = $car * 1e5 + $x; |
307 | $car = $prd - ($tmp = int($prd / $dd)) * $dd; |
308 | unshift(@d, $tmp); |
309 | } |
310 | } |
311 | else { |
312 | @d = @x; |
313 | } |
314 | (&external($sr, @q), &external($srem, @d, $zero)); |
315 | } else { |
316 | &external($sr, @q); |
317 | } |
318 | } |
319 | |
320 | # compute power of two numbers -- stolen from Knuth Vol 2 pg 233 |
321 | sub bpow { #(num_str, num_str) return num_str |
322 | local(*x, *y); ($x, $y) = (&bnorm($_[$[]), &bnorm($_[$[+1])); |
323 | if ($x eq 'NaN') { |
324 | 'NaN'; |
325 | } elsif ($y eq 'NaN') { |
326 | 'NaN'; |
327 | } elsif ($x eq '+1') { |
328 | '+1'; |
329 | } elsif ($x eq '-1') { |
330 | &bmod($x,2) ? '-1': '+1'; |
331 | } elsif ($y =~ /^-/) { |
332 | 'NaN'; |
333 | } elsif ($x eq '+0' && $y eq '+0') { |
334 | 'NaN'; |
335 | } else { |
336 | @x = &internal($x); |
337 | local(@pow2)=@x; |
338 | local(@pow)=&internal("+1"); |
339 | local($y1,$res,@tmp1,@tmp2)=(1); # need tmp to send to mul |
340 | while ($y ne '+0') { |
341 | ($y,$res)=&bdiv($y,2); |
342 | if ($res ne '+0') {@tmp=@pow2; @pow=&mul(*pow,*tmp);} |
343 | if ($y ne '+0') {@tmp=@pow2;@pow2=&mul(*pow2,*tmp);} |
344 | } |
345 | &external(@pow); |
346 | } |
347 | } |
348 | |
349 | 1; |