Introduction
Definition
A data structure is a way of organizing and storing data to perform operations efficiently. It defines the relationship between data elements and the operations that can be performed on them.
Operations
- Access: retrieve data from a specific location. Accessing an array element or a node in a linked list.
- Search: find a specific piece of data. Binary search for sorted arrays, linear search for unsorted arrays.
- Insertion: add data to a specific location. Inserting at the end of a linked list or at the top of a stack.
- Deletion: remove data from a specific location. Deleting a node from a linked list or popping from a stack.
- Traversal: visit every data element in a data structure. Common techniques include in-order, pre-order, and post-order traversal for trees.
- Sorting: arrange data elements in a specific order. QuickSort, MergeSort, and HeapSort are common sorting algorithms.
- Merging: combine two data structures into one. Merging two sorted arrays into a single sorted array.
Complexity
Time complexity
Describes the amount of time an algorithm takes concerning its input size. Big O notation is commonly used to express time complexity.
Space complexity
Describes the amount of memory an algorithm uses concerning its input size. Also expressed using Big O notation.
Trade-offs
- Different data structures have trade-offs in terms of time and space complexity.
- Choosing the right structure depends on the specific requirements of the problem at hand.
Considerations
- Understand the access patterns, insertion/deletion frequencies, and the size of the dataset.
- Consider the operations that need to be performed efficiently.