Frequency of each element in an array

[Shivani-Sharma-23]

Changes Proposed:

• Added C++ code for counting the frequency of each element in an array.
• The code utilizes a hash map to efficiently track the frequency of elements.

Motivation:

• Introducing a common algorithm used in data structures and algorithms to the DSA repository.
• This code snippet is useful for understanding hash maps and frequency counting, a fundamental concept in algorithmic problems.

Implementation Details:

• Created a new C++ source file named Frequency-of-element.cpp.
• Added a function countFrequency to count the frequency of elements in an array.
• Created a new Branch "Shivani"

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