Add project-euler.150
parent
303f9a3450
commit
3483317cfb
|
@ -0,0 +1,46 @@
|
|||
USING: kernel math math.ranges math.parser sequences io locals namespaces ;
|
||||
|
||||
IN: project-euler.150
|
||||
|
||||
: next-t ( t -- t' )
|
||||
615949 * 797807 + 1 20 shift rem ; inline
|
||||
|
||||
: next-s ( t -- s )
|
||||
1 19 shift - ; inline
|
||||
|
||||
: generate ( -- seq )
|
||||
0 500500 [ drop next-t dup next-s ] map nip ;
|
||||
|
||||
: start-index ( i -- n )
|
||||
dup 1- * 2/ ; inline
|
||||
|
||||
: partial-sums ( seq -- seq )
|
||||
0 [ + ] accumulate swap suffix ; inline
|
||||
|
||||
: as-triangle ( i seq -- slices )
|
||||
swap [1,b] [ [ start-index dup ] keep + rot <slice> ] with map ;
|
||||
|
||||
: sums-triangle ( -- seqs )
|
||||
1000 generate as-triangle [ partial-sums ] map ;
|
||||
|
||||
SYMBOL: best
|
||||
|
||||
: check-best ( i -- )
|
||||
best [ min ] change ; inline
|
||||
|
||||
:: (euler150) ( m -- n )
|
||||
[ [let | table [ sums-triangle ] |
|
||||
0 best set
|
||||
m [| x |
|
||||
x 1+ [| y |
|
||||
1000 x - [| z |
|
||||
x z + table nth
|
||||
[ y z + 1+ swap nth ] [ y swap nth ] bi -
|
||||
] map partial-sums infimum check-best
|
||||
] each
|
||||
] each
|
||||
]
|
||||
best get ] with-scope ;
|
||||
|
||||
: euler150 ( -- n )
|
||||
1000 (euler150) ;
|
Loading…
Reference in New Issue