Arrays
Array is a fundamental data structure in computer programming that stores a fixed-size, ordered sequence of elements of the same type. Arrays provide a simple and efficient way to store, access, and manipulate data.
Characteristics
- Fixed size: Arrays have a fixed size, determined at the time of their creation. The size cannot be changed after creation. - Homogeneous elements: All elements in an array must be of the same type. - Contiguous memory: Array elements are stored in contiguous memory locations, making it easy to calculate the memory address of each element. - Random access: Array elements can be accessed directly using their index in constant time.
Operations
Access
To access an element in an array, its index is used. Indices typically start at 0 and go up to the size of the array minus one.
- Time complexity: O(1)
Insertion
To insert an element into an array, all elements after the insertion point must be shifted to make room for the new element. In the worst case, when inserting at the beginning of the array, all elements must be shifted.
- Time complexity: O(n)
Deletion
To delete an element from an array, all elements after the deletion point must be shifted to fill the gap. In the worst case, when deleting the first element of the array, all remaining elements must be shifted.
- Time complexity: O(n)
Search
To search for an element in an array, a linear search can be performed by iterating through each element until the desired element is found.
- Time complexity: O(n)
Advantages and Disadvantages
Advantages:
- Fast random access - Simple implementation and usage
Disadvantages:
- Fixed size
- Inefficient insertion and deletion operations
Example Array Problems
- Searching for a target element in an array
- Reversing the elements of an array
- Rotating an array
- Calculating the sum of elements in an array