RosettaCodeData/Task/Look-and-say-sequence/Maxima/look-and-say-sequence-2.maxima
2023-09-01 09:35:06 -07:00

25 lines
658 B
Text

ciphers(n):=block(makelist(floor(mod(n, 10^(k+1)) / 10^k), k, 0,floor(log(n)/log(10))),reverse(%%));
collect(a) := block(
[n: length(ciphers(a)), b: [ ], x: ciphers(a)[1], m: 1],
for i from 2 thru n do
(if ciphers(a)[i] = x then m: m + 1 else (b: endcons([x, m], b), x: ciphers(a)[i], m: 1)),
b: endcons([x, m], b),
map(reverse,%%),
flatten(%%),
at(sum((part(%%,k))*y^(length(%%)-k),k,1,length(%%)),y=10)
)$
block(i:1,append([i],makelist(i:collect(i),9)),table_form(%%));
/* matrix(
[1],
[11],
[21],
[1211],
[111221],
[312211],
[13112221],
[1113213211],
[31131211131221],
[13211311123113112211]
) */