freeCodeCamp/Data Structures/circularQueue.js

43 lines
861 B
JavaScript

class CircularQueue {
constructor(size) {
this.queue = [];
this.read = 0;
this.write = 0;
this.max = size - 1;
while (size > 0) {
this.queue.push(null);
size--;
}
}
print() {
return this.queue;
}
enqueue(item) {
// Only change code below this line
if (this.queue[this.write] === null) {
this.queue[this.write++] = item;
if (this.write > this.max) this.write = 0;
return item;
}
return null;
// Only change code above this line
}
dequeue() {
// Only change code below this line
if (this.queue[this.read] === null) {
return null;
}
const item = this.queue[this.read];
this.queue[this.read++] = null;
if (this.read > this.max) this.read = 0;
return item;
// Only change code above this line
}
}
const q = new CircularQueue(5);