2.2 KiB
2.2 KiB
title |
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Create a Queue Class |
Create a Queue Class
Method:
-
A Queue is an abstract Data Structure.
-
A Queue folow FIFO/LILO principle.
-
In this challenge we nede to implement
enqueue()
,dequeue()
,front()
,size()
,isEmpty()
methods.enqueue()
- This method adds the element to the queue.dequeue()
- This method removes the first element from the queue.front()
- This method returns the first element in the queue that'd be dequeue'd.size()
- This method returns the size of the queue.isEmpty()
- This method returns if the queue is empty.
-
DS Access Search Insert Delete Queue n n 1 1
Solution:
Basic:
Note:
- This solution is not exactly a queue, the shift() method used in the dequeue() method is of complexity
O(n)
and notO(1)
. However, the advanced solution rectifies this and uses Object(HashTables) instead of Array to implement Queue.
function Queue () {
var collection = [];
this.print = function() {
console.log(collection);
};
this.enqueue = function(val){
collection.push(val);
};
this.dequeue = function(){
return collection.shift();
}
this.front = function(){
return collection[0];
}
this.size = function(){
return collection.length;
}
this.isEmpty = function(){
return collection.length === 0;
}
}
Advanced - ES6 class syntax:
class Queue {
constructor(){
this.collection = {};
this.start = 0;
this.end = 0;
}
print(){
console.log(this.collection);
}
enqueue(val){
this.collection[this.end++] = val;
}
dequeue(){
return this.collection[this.start++];
}
front(){
return this.collection[this.start];
}
size(){
return this.end - this.start;
}
isEmpty(){
return this.size() === 0;
}
}