Project Euler

[ホーム](https://redmine.noppi.jp) - [[Wiki|Project Euler]]

# [[Problem 10]]

```scheme

#!r6rs

#!chezscheme

(import (chezscheme))

(define answer-10

  (let ((table (make-vector 2000001 #t))

        (count (isqrt 2000000)))

    (vector-set! table 0 #f)

    (vector-set! table 1 #f)

    (let loop1 ((index 2))

      (cond

        [(< count index)

         (let loop2 ((index 0) (result 0))

           (cond

             [(< 2000000 index) result]

             [(vector-ref table index)

              (loop2 (add1 index) (+ result index))]

             [else (loop2 (add1 index) result)]))]

        [(vector-ref table index)

         (let loop3 ((current (* index 2)))

           (cond

             [(< 2000000 current)

              (loop1 (add1 index))]

             [else

               (vector-set! table current #f)

               (loop3 (+ current index))]))]

        [else (loop1 (add1 index))]))))

(printf "10: ~D~%" answer-10)

```