! Inclusion-exclusion principle
+<PRIVATE
+
+: sum-divisible-by ( target n -- m )
+ [ /i dup 1+ * ] keep * 2 /i ;
+
+PRIVATE>
+
: euler001 ( -- answer )
- 0 999 3 <range> sum 0 999 5 <range> sum + 0 999 15 <range> sum - ;
+ 999 3 sum-divisible-by
+ 999 5 sum-divisible-by +
+ 999 15 sum-divisible-by - ;
! [ euler001 ] 100 ave-time
! 0 ms run / 0 ms GC ave time - 100 trials
! -------------------
: euler001a ( -- answer )
- 1000 [ dup 5 mod swap 3 mod [ zero? ] either? ] filter sum ;
+ 0 999 3 <range> sum 0 999 5 <range> sum + 0 999 15 <range> sum - ;
! [ euler001a ] 100 ave-time
! 0 ms run / 0 ms GC ave time - 100 trials
+
+: euler001b ( -- answer )
+ 1000 [ dup 5 mod swap 3 mod [ zero? ] either? ] filter sum ;
+
+! [ euler001b ] 100 ave-time
+! 0 ms run / 0 ms GC ave time - 100 trials
+
MAIN: euler001