C HashMap Implementation

This project is a custom implementation of a HashMap data structure in C, designed to store words and their frequencies. It includes basic operations like insertion, lookup, and existence checks. The program also measures the time taken to perform existence checks for a large number of randomly generated words.

Project Structure

• main.c: Contains the main function to initialize the HashMap, insert entries, and check if entries exist in the map.
• StringCountHashMap.h: Header file that defines the String HashMap structure and function prototypes.
• StringCountHashMap.c: Source file that implements the HashMap operations, including: createHashMap: Creates a new HashMap with a specified initial capacity. insertEntry: Inserts a key-value pair (word and frequency) into the HashMap. getOrDefault: Gets the frequency of a word if it exists, or returns 0 if it doesn’t. existInTable: Checks if a word exists in the HashMap. printHashMap: Prints all words and their frequencies in the HashMap.
• IntHashMap.h:Header file that defines the Integer HashMap structure and function prototypes.
• IntHashMap.c: Source file that implements the HashMap operations and include the same function as that of string hash map.

Installation and Compilation

Install MinGW (for Windows users):

Download and install MinGW from here. Add C:\MinGW\bin to your system's PATH environment variable. Compile the Project:

Open a terminal in the project directory. Run the following commands to compile the project:

mingw32-make

Run the Program:

Execute the compiled program:

./hash_demo

Usage The program will:

Create a HashMap with twice the capacity of the number of words to be checked. Generate random words, insert them into the HashMap, and set their frequency. Check if the words exist in the map and print the time taken for the existence checks. You can modify the number of words to be generated and checked by adjusting the WORDSLEN constant in main.c.

Example Output

Time spent for checking 100000 words: 0.009000 seconds
Time spent for checking 100000 numbers: 0.004000 seconds

Implementation Details Hash Function The HashMap uses a custom hash function to calculate the index for each word. This can be adjusted or optimized further if needed.

Memory Management The HashMap dynamically allocates memory for each entry’s key. Make sure to free the allocated memory after use to avoid memory leaks.