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- "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;
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