Pythagorean quadruples: Difference between revisions
Added solution for EDSAC
m (→{{header|Wren}}: Changed to Wren S/H) |
(Added solution for EDSAC) |
||
Line 665:
<pre>The values of d <= 2200 which can't be represented:
1 2 4 5 8 10 16 20 32 40 64 80 128 160 256 320 512 640 1024 1280 2048</pre>
=={{header|EDSAC order code}}==
A solution from first principles would probably take a long time on EDSAC, so we use the theoretical results [https://mathoverflow.net/questions/90914/sums-of-three-non-zero-squares quoted in MathOverflow]. From these it follows easily that if d is a power of 2, or 5 times a power of 2, then d^2 is not the sum of three non-zero squares. The converse does not follow, but if d is a counterexample then d^2 exceeds 5*(10^10), and therefore d exceeds the limit in the task description. The EDSAC output thus consists of two interleaved arrays, as in the AppleScript solution.
<syntaxhighlight lang="edsac">
[Pythagorean quadruples - Rosetta Code
EDSAC program, Initial Orders 2]
[Arrange the storage]
T46K P56F [N parameter: modified library s/r P7 to print integer]
T47K P106F [M parameter: main routine]
[Library subroutine M3, prints header at load time.
Here, header leaves teleprinter in figures mode.]
PFGKIFAFRDLFUFOFE@A6FG@E8FEZPF
*NUMBERS!WHOSE!SQUARES!ARE!NOT!THE!SUM!
OF!THREE!NONZERO!SQUARES@&MAXIMUM#!V!
..PK [after header, blank tape and PK (WWG, 1951, page 91)]
[------------------------------------------------------------------------------]
[Main routine]
E25K TM GK [load at address specified by M parameter]
[Constants]
[0] P1100F [limit, right-justified, e.g. P1100F for 2200]
[1] !F [teleprinter space]
[2] @F [carriage return]
[3] &F [line feed]
[4] K4096F [teleprinter null]
[5] PD [17-bit constant 1]
[6] P2D [17-bit constant 5]
[Variables]
[7] PF [2^m, where m = 0, 1, 2, ...]
[8] PF [5*2^n, where n = 0, 1, 2, ...]
[Enter here, with acc = 0]
[Complete header by printing limit]
[9] A4@ T1F [print leading zeros as nulls]
A@ TF [pass limit to print subroutine in 0F]
[13] A13@ GN [call print subroutine; leaves acc clear]
O2@ O3@ [print new line]
[Initialize variables]
A5@ T7@ [2^m := 1]
A6@ T8@ [5*2^n := 5]
[Loop back to here after printing number]
[Print 2^m or 5*2^n, whichever is smaller]
[21] A7@ S8@ [compare values]
E28@ [jump if 5*2^n is smaller]
A8@ [else restore 2^m in acc]
LD U7@ [double value in memory]
E32@ [jump to common code]
[28] T4F [clear acc]
A8@ [acc := 5*2^n]
LD U8@ [double value in memory]
[32] RD [common code: undo doubling in acc]
TF [pass number to print subroutine in 0F]
A@ SF [test for number > limit]
G42@ [jump to exit if so]
O1@ [print space before number]
T4F [clear acc]
[39] A39@ GN [call print subroutine; leaves acc clear]
E21@ [loop back for next number]
[Here when done]
[42] O2@ O3@ [print new line]
O4@ [print null to flush teleprinter buffer]
ZF [halt the machine]
[------------------------------------------------------------]
[Subroutine to print 17-bit non-negative integer
Parameters: 0F = integer to be printed (not preserved)
1F = character for leading zero
(preserved; typically null, space or zero)
Workspace: 4F, 5F
Even address; 39 locations]
E25K TN [load at address specified by N parameter]
GKA3FT34@A1FT35@S37@T36@T4DAFT4FH38@V4FRDA4D
R1024FH30@E23@O35@A2FT36@T5FV4DYFL8FT4DA5F
L1024FUFA36@G16@OFTFT35@A36@G17@ZFPFPFP4FZ219D
E25K TM GK [M parameter again]
E9Z [define entry point]
PF [acc = 0 on entry]
</syntaxhighlight>
{{out}}
<pre>
NUMBERS WHOSE SQUARES ARE NOT THE SUM OF THREE NONZERO SQUARES
MAXIMUM = 2200
1 2 4 5 8 10 16 20 32 40 64 80 128 160 256 320 512 640 1024 1280 2048
</pre>
=={{header|FreeBASIC}}==
| |||