--- id: 587d8254367417b2b2512c6f title: Eseguire un controllo di sottoinsieme su due insiemi di dati challengeType: 1 forumTopicId: 301707 dashedName: perform-a-subset-check-on-two-sets-of-data --- # --description-- In questo esercizio, eseguiremo un test subset su 2 set di dati. Creeremo un metodo sulla nostra struttura di dati `Set` chiamato `isSubsetOf`. Questo confronterà il primo set con il secondo, e se il primo set è pienamente contenuto nel secondo, restituirà `true`. Per esempio, se `setA = ['a','b']` e `setB = ['a','b','c','d']`, allora `setA` è un subset di `setB`, quindi `setA.isSubsetOf(setB)` dovrebbe restituire `true`. # --hints-- La tua classe `Set` dovrebbe avere un metodo `isSubsetOf`. ```js assert( (function () { var test = new Set(); return typeof test.isSubsetOf === 'function'; })() ); ``` Il primo `Set` dovrebbe essere contenuto nel secondo `Set` ```js assert( (function () { var setA = new Set(); var setB = new Set(); setA.add('a'); setB.add('b'); setB.add('c'); setB.add('a'); setB.add('d'); var aIsSubsetOfB = setA.isSubsetOf(setB); return aIsSubsetOfB === true; })() ); ``` `['a', 'b'].isSubsetOf(['a', 'b', 'c', 'd'])` dovrebbe restituire `true` ```js assert( (function () { var setA = new Set(); var setB = new Set(); setA.add('a'); setA.add('b'); setB.add('a'); setB.add('b'); setB.add('c'); setB.add('d'); var aIsSubsetOfB = setA.isSubsetOf(setB); return aIsSubsetOfB === true; })() ); ``` `['a', 'b', 'c'].isSubsetOf(['a', 'b'])` dovrebbe restituire `false` ```js assert( (function () { var setA = new Set(); var setB = new Set(); setA.add('a'); setA.add('b'); setA.add('c'); setB.add('a'); setB.add('b'); var aIsSubsetOfB = setA.isSubsetOf(setB); return aIsSubsetOfB === false; })() ); ``` `[].isSubsetOf([])` dovrebbe restituire `true` ```js assert( (function () { var setA = new Set(); var setB = new Set(); var aIsSubsetOfB = setA.isSubsetOf(setB); return aIsSubsetOfB === true; })() ); ``` `['a', 'b'].isSubsetOf(['c', 'd'])` dovrebbe restituire `false` ```js assert( (function () { var setA = new Set(); var setB = new Set(); setA.add('a'); setA.add('b'); setB.add('c'); setB.add('d'); var aIsSubsetOfB = setA.isSubsetOf(setB); return aIsSubsetOfB === false; })() ); ``` # --seed-- ## --seed-contents-- ```js class Set { constructor() { // This will hold the set this.dictionary = {}; this.length = 0; } // This method will check for the presence of an element and return true or false has(element) { return this.dictionary[element] !== undefined; } // This method will return all the values in the set values() { return Object.keys(this.dictionary); } // This method will add an element to the set add(element) { if (!this.has(element)) { this.dictionary[element] = true; this.length++; return true; } return false; } // This method will remove an element from a set remove(element) { if (this.has(element)) { delete this.dictionary[element]; this.length--; return true; } return false; } // This method will return the size of the set size() { return this.length; } // This is our union method union(set) { const newSet = new Set(); this.values().forEach(value => { newSet.add(value); }) set.values().forEach(value => { newSet.add(value); }) return newSet; } // This is our intersection method intersection(set) { const newSet = new Set(); let largeSet; let smallSet; if (this.dictionary.length > set.length) { largeSet = this; smallSet = set; } else { largeSet = set; smallSet = this; } smallSet.values().forEach(value => { if (largeSet.dictionary[value]) { newSet.add(value); } }) return newSet; } difference(set) { const newSet = new Set(); this.values().forEach(value => { if (!set.dictionary[value]) { newSet.add(value); } }) return newSet; } // Only change code below this line // Only change code above this line } ``` # --solutions-- ```js class Set { constructor() { this.dictionary = {}; this.length = 0; } has(element) { return this.dictionary[element] !== undefined; } values() { return Object.keys(this.dictionary); } add(element) { if (!this.has(element)) { this.dictionary[element] = true; this.length++; return true; } return false; } remove(element) { if (this.has(element)) { delete this.dictionary[element]; this.length--; return true; } return false; } size() { return this.length; } union(set) { const newSet = new Set(); this.values().forEach(value => { newSet.add(value); }) set.values().forEach(value => { newSet.add(value); }) return newSet; } intersection(set) { const newSet = new Set(); let largeSet; let smallSet; if (this.dictionary.length > set.length) { largeSet = this; smallSet = set; } else { largeSet = set; smallSet = this; } smallSet.values().forEach(value => { if (largeSet.dictionary[value]) { newSet.add(value); } }) return newSet; } difference(set) { const newSet = new Set(); this.values().forEach(value => { if (!set.dictionary[value]) { newSet.add(value); } }) return newSet; } isSubsetOf(set) { for(const value of this.values()){ if(!set.dictionary[value]) return false; } return true } } ```