RosettaCodeData/Task/Permutations-Derangements/EchoLisp/permutations-derangements-2.echolisp
2016-12-05 23:44:36 +01:00

20 lines
475 B
Text

(derangements 4)
→ ((3 0 1 2) (2 0 3 1) (2 3 0 1) (3 2 0 1) (3 2 1 0) (2 3 1 0) (1 2 3 0) (1 3 0 2) (1 0 3 2))
;; generated versus computed
(for ((i 10)) (writeln i '| (count-derangements i) (!n i)))
0 | 1 1
1 | 0 0
2 | 1 1
3 | 2 2
4 | 9 9
5 | 44 44
6 | 265 265
7 | 1854 1854
8 | 14833 14833
9 | 133496 133496
(!n 20)
→ 895014631192902121