dict.h

#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

typedef struct
{
	char **keys; // pointer to a pointer to a char, it's a memory address
	uint64_t **values;
	int size;	  // max number of key-value elements
	int occupied; // number of key-value elements created
} Dict;

void initDict(Dict *dict, int size, int maxKeyStringSize, int maxValueStringSize)
{
	*dict = (Dict){
		.keys = malloc(sizeof(char *) * size),		 // char* is pointer to a char, it's a memory address
		.values = malloc(sizeof(uint64_t *) * size), // malloc reserves x memory
		.size = size,
		.occupied = 0};

	int i;
	for (i = 0; i < size; i++)
	{
		dict->keys[i] = malloc(maxKeyStringSize); // reserves x memory for each key element of the dict
		dict->values[i] = malloc(maxValueStringSize);
	}
}

bool addToDict(Dict *dict, char *key, uint64_t *value)
{
	// checks if the key already exists in a key-value element
	int i;
	for (i = 0; i < dict->size; i++)
	{
		if (!strcmp(dict->keys[i], key))
		{
			// if key-value element already exists then overwrite the value
			memcpy(dict->values[i], value, sizeof(uint64_t));
			return true;
		}
	}

	// checks if the dict is already full
	if (dict->size == dict->occupied)
	{
		return false;
	}

	// add new key-value element to dict
	// we can use dict->occupied as index
	// if key and value are too long, they will be truncated
	strcpy(dict->keys[dict->occupied], key);
	memcpy(dict->values[dict->occupied], value, sizeof(uint64_t));
	dict->occupied++;

	return true;
}

uint64_t getDictValueAt(Dict *dict, char *key)
{
	int i;
	for (i = 0; i < dict->size; i++)
	{
		if (!strcmp(dict->keys[i], key))
		{
			return (uint64_t)*dict->values[i];
		}
	}

	return 0;
}