Set: Set data structure allow to add data to a container.
This custom Set implementation in JavaScript uses an array (collection[]) to store unique values, similar to the built-in Set object. It provides methods to add, remove, check, and retrieve the size of the collection while ensuring each element is unique.
Methods:
- size(): Returns the number of elements in the set.
- has(item): Checks if the set contains a specific item.
- add(item): Adds a new item to the set if it doesn’t already exist.
- delete(item): Removes an item from the set if it exists.
- clear(): Removes all items from the set.
- values(): Returns all the items in the set.
Here is an example of set internal implementation.
const Set=function(){
let collection=[];
this.size=function(){
return collection.length;
}
this.has=function(item){
return collection.indexOf(item)!==-1
}
this.add=function(item){
if(!this.has(item)){
collection.push(item)
return true;
}
return false;
}
this.delete=function(item){
if(!this.has(item)){
return false;
}else{
let index=collection.indexOf(item);
collection.splice(index,1);
return true;
}
}
this.clear=function(){
collection=[];
}
this.values=function(){
return collection;
}
}
let set=new Set();
console.log(set.size());
console.log(set.add(1));
console.log(set.add(2));
console.log(set.size());
console.log(set.delete(2));
console.log(set.delete(2));
console.log(set.size());
Time Complexity:
- size(): O(1) - Simply returns the length of the array.
- has(item): O(n) - The indexOf() method is used, which performs a linear search through the array.
- add(item): O(n) - Before adding, it calls has(item) which is O(n), and if the item doesn’t exist, push() is O(1).
- delete(item): O(n) - It uses indexOf() to find the index of the item, which is O(n), and then splice() to remove it, which is also O(n).
- clear(): O(1) - Just resets the array to an empty array.
- values(): O(1) - Returns the reference to the array. > Any comments or suggestions are welcome.
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