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Stacks follows these principles :
- FILO : First in last out .
- LIFO : Last in first out .
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Terminology :
- Top : is the newest element added to the top of the stack .
- Push O (1) : Adds an element to the top of stack , using linkedlist will make the current top equals new node and the old top will point to the new top .
- Pop O (1) : Removes the top item from the stack and make the top the top.next .
- Peek O (1) : Returns the top element of the stack .
- isEmpty O (1) : Returns boolean true if the stack is empty .
Def. Linear Data structure that have two pointers the front which will be dequeued from and the rear which will add to queue after it .
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Queues follows These principles :
- FIFO : First in first out .
- LILI : Last in last out .
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Terminology :
- Front : The front element which is the first element added (The oldest)
- Rear : The latest element added which will be added after it .
- enqueue O(1): Add a node to the rear of the queue using a pointer connectiong rear elements.next .
- dequeue O(1): Removing the front element using the pointer to be front.next.next .
- peek O(1): Returns the front element of the queue which is the oldest element or first element added .
- isEmpty O(1): Returns boolean true if the queue is empty .