These are the summary of my learnings from an udemy course: "Data Structures & Algo in swift"

1. Constant Time
2. Linear Time
3. Quadratic Time
4. Logarithmic Time - Binary Search
5. Quasilinear Time

• Root
• Child -> left child & right child
• Leaf

• Elements are connected to each other by reference called Nodes

• 1st node in the linked list is called Head

• Last node is called Tail node

  Operations: - push - append - insert - pop - removeLast - remove

• Push
• Pop

• Peek
• Enqueue
• Dequeue

• Base case - which stops the recursion.
• Recursive case

• Depth First Traversal
• Level Order Traversal
• Search
• Binary Tree (can have max of: 2 Children only - left & right)
  • In order Traversal -> leftChild -> Node -> RightChild
  • Post order Traversal -> leftChild -> RightChild -> Node
  • Pre order Traversal -> Node -> leftChild -> rightChild
• Binary Search Tree

• O(n)

• Sorted array
• Middle index - left or right
• Best Time: O(1)
• Worst Time: O(log n)

• Unsorted
• Best Time: O(n) (if already sorted)
• Worst Time: O(n^2)

• Swap the minimum element in the array with current index
• Move to next index and repeat step 1
• Best Time: O(n^2)
• Worst Time: O(n^2)

• Unsorted
• Best Time: O(n)
• Worst Time: O(n^2)

Consist of

• Vertices / Vertex
• Edges / Edge

• Weighted graphs
• Directed graphs
• Undirected graphs (bi-directional)

• Most commonly/widely used way to create and represent a graph