Smallest square that begins with n: Difference between revisions

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=={{header|REXX}}==

A little extra code was added to display the results in a table, &nbsp; the width of the table can be specified.

Also, the output display was generalized so that if a larger number than expected won't be truncated.

<lang rexx>/*REXX program finds and displays (positive integers) squares that begin with N. */

numeric digits 20 /*ensure that large numbers can be used*/

parse arg n cols . /*get optional number of primes to find*/

if n=='' | n=="," then n= 50 /*Not specified? Then assume default.*/

if cols=='' | cols=="," then cols= 10 /* " " " " " */

w= 10 /*width of a number in any column. */

say ' index │'center(" smallest squares that begin with N", 1 + cols*(w+1) )

say '───────┼'center("" , 1 + cols*(w+1), '─')

#= 0 /*initialize the count of found numbers*/

idx= 1

$= /*a list of additive primes (so far). */

do j=1 while #<n /*keep searching 'til enough nums found*/

do k=1 until pos(j, k * k)==1 /*compute a square of some number. */

end /*k*/

#= # + 1 /*bump the count of numbers found. */

c= commas(k*k); L= length(c) /*calculate K**2 (with commas) and L */

$= $ right( c, max(w, L) ) /*add square to $ list, allow for big N*/

if #//cols\==0 then iterate /*have we populated a line of output? */

say center(idx, 7)'│' substr($, 2); $= /*display what we have so far (cols). */

idx= idx + cols

end /*j*/

if $\=='' then say center(idx, 7)"│" substr($, 2) /*possible display residual output.*/

exit 0 /*stick a fork in it, we're all done. */

/*──────────────────────────────────────────────────────────────────────────────────────*/

commas: parse arg ?; do jc=length(?)-3 to 1 by -3; ?=insert(',', ?, jc); end; return ?</lang>

{{out|output|text=&nbsp; when using the default inputs:}}

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index │ smallest squares that begin with N

───────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────

1 │ 1 25 36 4 529 64 729 81 9 100

11 │ 1,156 121 1,369 144 1,521 16 1,764 1,849 196 2,025

21 │ 2,116 225 2,304 2,401 25 2,601 2,704 289 2,916 3,025

31 │ 3,136 324 3,364 3,481 35,344 36 3,721 3,844 3,969 400

41 │ 41,209 4,225 4,356 441 45,369 4,624 4,761 484 49 5,041