Anonymous user
Catalan numbers/Pascal's triangle: Difference between revisions
Added EchoLisp
(Added EchoLisp) |
|||
Line 275:
{{out}}
<pre>1 2 5 14 42 132 429 1430 4862 16796 58786 208012 742900 2674440 9694845 </pre>
=={{header|EchoLisp}}==
<lang scheme>
(define dim 100)
(define-syntax-rule (Tidx i j) (+ i (* dim j)))
;; generates Catalan's triangle
;; T (i , j) = T(i-1,j) + T (i, j-1)
(define (T n)
(define i (modulo n dim))
(define j (quotient n dim))
(cond
((zero? i) 1) ;; left column = 1
((= i j) (T (Tidx (1- i) j))) ;; diagonal value = left value
(else (+ (T (Tidx (1- i) j)) (T (Tidx i (1- j)))))))
(remember 'T #(1))
</lang>
{{out}}
<lang scheme>
;; take elements on diagonal = Catalan numbers
(for ((i (in-range 0 16))) (write (T (Tidx i i))))
</lang>
→ 1 1 2 5 14 42 132 429 1430 4862 16796 58786 208012 742900 2674440 9694845
</lang>
=={{header|Elixir}}==
| |||