(euler060) ( -- primes )

Vocabulary

project-euler.060

Inputs

None

Outputs

primes

an object

Definition

USING: backtrack backtrack.private combinators.short-circuit
kernel math math.primes sequences ;

IN: project-euler.060

:: (euler060) ( -- primes )
    [
        1/0. :> result! 10000 primes-upto :> primes1 primes1
        amb-integer :> i i primes1 nth :> a primes1 i 1 +
        tail-slice
        [ { [ 4 * a + result < ] [ a prime-pair? ] } 1&& ]
        filter :> primes2 primes2 amb-integer :> j j primes2 nth
        :> b primes2 j 1 + tail-slice
        [ { [ 3 * a b + + result < ] [ b prime-pair? ] } 1&& ]
        filter :> primes3 primes3 amb-integer :> k k primes3 nth
        :> c primes3 k 1 + tail-slice [
            { [ 2 * a b c + + + result < ] [ c prime-pair? ] }
            1&&
        ] filter
        :> primes4 primes4 amb-integer :> l l primes4 nth
        :> d primes4 l 1 + tail-slice [
            { [ a b c d + + + + result < ] [ d prime-pair? ] }
            1&&
        ] filter :> primes5 primes5 amb-lazy :> e
        { a b c d e } dup sum result!
    ] bag-of last ;