| "use strict"; |
| |
| /** |
| * intersect creates Set containing the intersection of elements between all sets |
| * @param {Set[]} sets an array of sets being checked for shared elements |
| * @returns {Set<TODO>} returns a new Set containing the intersecting items |
| */ |
| const intersect = sets => { |
| if (sets.length === 0) return new Set(); |
| if (sets.length === 1) return new Set(sets[0]); |
| let minSize = Infinity; |
| let minIndex = -1; |
| for (let i = 0; i < sets.length; i++) { |
| const size = sets[i].size; |
| if (size < minSize) { |
| minIndex = i; |
| minSize = size; |
| } |
| } |
| const current = new Set(sets[minIndex]); |
| for (let i = 0; i < sets.length; i++) { |
| if (i === minIndex) continue; |
| const set = sets[i]; |
| for (const item of current) { |
| if (!set.has(item)) { |
| current.delete(item); |
| } |
| } |
| } |
| return current; |
| }; |
| |
| /** |
| * Checks if a set is the subset of another set |
| * @param {Set<TODO>} bigSet a Set which contains the original elements to compare against |
| * @param {Set<TODO>} smallSet the set whos elements might be contained inside of bigSet |
| * @returns {boolean} returns true if smallSet contains all elements inside of the bigSet |
| */ |
| const isSubset = (bigSet, smallSet) => { |
| if (bigSet.size < smallSet.size) return false; |
| for (const item of smallSet) { |
| if (!bigSet.has(item)) return false; |
| } |
| return true; |
| }; |
| |
| exports.intersect = intersect; |
| exports.isSubset = isSubset; |