Two sum: Difference between revisions
→JS ES6: Added comments on access to indices, and skipping the 'lower triangle' of a cartesian grid (where iy < ix)
m (→ES6: Minor simplification) |
(→JS ES6: Added comments on access to indices, and skipping the 'lower triangle' of a cartesian grid (where iy < ix)) |
||
Line 244:
// summingPairIndices :: -> Int -> [Int] -> [(Int, Int)]
let summingPairIndices = (n, xs) =>
// Javascript map functions have access to the array index
// in their second argument.
concatMap((x, ix) => concatMap((y, iy) =>
iy
// skipping the 'lower triangle' (y < x)
// of the cartesian product grid
x + y === n ? [
[
] : []
), xs), xs);
| |||