Smallest square that begins with n: Difference between revisions

=={{header|Picat}}==

===Recursion and string approach===

<lang Picat>import util.

main =>

println([S : N in 1..49, S = smallest_square(N)]).

smallest_square(N) = Square =>

smallest_square(N.to_string,1,Square).

smallest_square(N,S,SS) :-

SS = S*S,

find((SS).to_string,N,1,_).

smallest_square(N,S,SS) :-

smallest_square(N,S+1,SS).</lang>

{{out}}

<pre>[1,25,36,4,529,64,729,81,9,100,1156,121,1369,144,1521,16,1764,1849,196,2025,2116,225,2304,2401,25,2601,2704,289,2916,3025,3136,324,3364,3481,35344,36,3721,3844,3969,400,41209,4225,4356,441,45369,4624,4761,484,49]</pre>

===Iterative===

<lang Picat>main =>

println([S : N in 1..49, S = smallest_square2(N)]).

smallest_square2(N) = Ret =>

I = 1,

Found = false,

while (Found == false)

Square = I*I,

while (Square > N)

Square := Square // 10

end,

if Square == N then

Found := I*I

end,

I := I + 1

end,

Ret = Found.</lang>

{{out}}

<pre>[1,25,36,4,529,64,729,81,9,100,1156,121,1369,144,1521,16,1764,1849,196,2025,2116,225,2304,2401,25,2601,2704,289,2916,3025,3136,324,3364,3481,35344,36,3721,3844,3969,400,41209,4225,4356,441,45369,4624,4761,484,49]</pre>