Sum multiples of 3 and 5: Difference between revisions
Content added Content deleted
| Line 1,678: | Line 1,678: | ||
=={{header|J}}== |
=={{header|J}}== |
||
<lang J> |
<lang J> |
||
mp =: $:~ :(+/ .*) NB. matrix product |
mp =: $:~ :(+/ .*) NB. matrix product |
||
| Line 1,721: | Line 1,720: | ||
(0,.10 10000 10000000000000000000x)+`-/"1@:(sum_arithmetic_series"1@:(,"1 0"1 _))3 5 15x |
(0,.10 10000 10000000000000000000x)+`-/"1@:(sum_arithmetic_series"1@:(,"1 0"1 _))3 5 15x |
||
23 23331668 23333333333333333331666666666666666668 |
23 23331668 23333333333333333331666666666666666668 |
||
</lang> |
|||
=== Simple Solution === |
|||
The problem can also be solved with a simple use of inclusion/exclusion; this solution is more in keeping with how one could approach the problem from a more traditional language. |
|||
<lang J> |
|||
NB. Naive method |
|||
NB. joins two lists of the multiples of 3 and 5, then uses the ~. operator to remove duplicates. |
|||
echo 'The sum of the multiples of 3 or 5 < 1000 is ', ": +/ ~. (3*i.334), (5*i.200) |
|||
NB. inclusion/exclusion |
|||
triangular =: monad : '(y*(y + 1)) % 2' |
|||
sumdiv =: dyad : '(triangular <. x % y) * y' |
|||
echo 'For 10^20 - 1, the sum is ', ": +/ 99999999999999999999x sumdiv 3 5 _15 |
|||
exit '' |
|||
</lang> |
</lang> |
||