> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/sidef-lang/programming_tasks/s/sum_and_product_puzzle.md).

# Sum and product puzzle

```ruby
func grep_uniq(a, by) { a.group_by{ .(by) }.values.grep{.len == 1}.map{_[0]} }
func sums     (n)     { 2 .. n//2 -> map {|i| [i, n-i] } }

var pairs = {|i| ([i] ~X (i+1 .. 98))... }.map(2..97)

var p_uniq = Hash()
p_uniq{grep_uniq(pairs, :prod).map { .to_s }...} = ()

var s_pairs = pairs.grep {|p| sums(p.sum).all { !p_uniq.contains(.to_s) } }
var p_pairs = grep_uniq(s_pairs, :prod)
var f_pairs = grep_uniq(p_pairs, :sum)

f_pairs.each { |p| printf("X = %d, Y = %d\n", p...) }
```

## Output:

```
X = 4, Y = 13
```