diff --git a/arrays/arrays.c b/arrays/arrays.c index 48c23e7..00378e9 100644 --- a/arrays/arrays.c +++ b/arrays/arrays.c @@ -3,13 +3,13 @@ #include #include -typedef struct Array { - int capacity; // How many elements can this array hold? - int count; // How many states does the array currently hold? - char **elements; // The string elements contained in the array +typedef struct Array +{ + int capacity; // How many elements can this array hold? + int count; // How many states does the array currently hold? + char **elements; // The string elements contained in the array } Array; - /************************************ * * CREATE, DESTROY, RESIZE FUNCTIONS @@ -19,45 +19,69 @@ typedef struct Array { /***** * Allocate memory for a new array *****/ -Array *create_array (int capacity) { - // Allocate memory for the Array struct +// gcc -o arrays arrays.c +Array *create_array(int capacity) +{ + // Allocate memory (malloc) for the Array struct + Array *arr = malloc(sizeof(Array)); // Set initial values for capacity and count - + arr->capacity = capacity; + arr->count = 0; // Allocate memory for elements + arr->elements = malloc(capacity * sizeof(char *)); + // arr->elements = calloc(capacity, sizeof(char *)); + return arr; } - /***** * Free memory for an array and all of its stored elements *****/ -void destroy_array(Array *arr) { +void destroy_array(Array *arr) +{ // Free all elements + for (int i = 0; i < arr->count; i++) + { + arr->elements[i] = NULL; + free(arr->elements[i]); //marks memory ready to be reused by something else + } // Free array - + free(arr->elements); + free(arr); } /***** * Create a new elements array with double capacity and copy elements * from old to new *****/ -void resize_array(Array *arr) { +void resize_array(Array *arr) +{ // Create a new element storage with double capacity + char **storage = calloc((2 * arr->capacity), sizeof(char *)); // Copy elements into the new storage + for (int i = 0; i < arr->count; i++) + { + storage[i] = arr->elements[i]; + } // Free the old elements array (but NOT the strings they point to) + for (int i = 0; i < arr->count; i++) + { + arr->elements[i] = NULL; + free(arr->elements[i]); + } + free(arr->elements); // Update the elements and capacity to new values - + arr->elements = storage; + arr->capacity = arr->capacity * 2; } - - /************************************ * * ARRAY FUNCTIONS @@ -69,43 +93,68 @@ void resize_array(Array *arr) { * * Throw an error if the index is out of range. *****/ -char *arr_read(Array *arr, int index) { +char *arr_read(Array *arr, int index) +{ // Throw an error if the index is greater than the current count + if (arr->count < index) + { + printf("Index is higher that current count."); + exit(1); + } // Otherwise, return the element at the given index + return arr->elements[index]; } - /***** * Insert an element to the array at the given index *****/ -void arr_insert(Array *arr, char *element, int index) { +void arr_insert(Array *arr, char *element, int index) +{ // Throw an error if the index is greater than the current count + if (index > arr->count) + { + printf("Index is greater than current count."); + exit(1); + } // Resize the array if the number of elements is over capacity + if (arr->count + 1 > arr->capacity) + { + resize_array(arr); + } // Move every element after the insert index to the right one position - + for (int i = index; i < arr->count; i++) + { + arr->elements[i + 1] = arr->elements[i]; + } // Copy the element and add it to the array + arr->elements[index] = element; // Increment count by 1 - + arr->count++; } /***** * Append an element to the end of the array *****/ -void arr_append(Array *arr, char *element) { +void arr_append(Array *arr, char *element) +{ // Resize the array if the number of elements is over capacity // or throw an error if resize isn't implemented yet. - + if (arr->capacity < arr->count + 1) + { + resize_array(arr); + } // Copy the element and add it to the end of the array + arr->elements[arr->count] = element; // Increment count by 1 - + arr->count++; } /***** @@ -114,33 +163,49 @@ void arr_append(Array *arr, char *element) { * * Throw an error if the value is not found. *****/ -void arr_remove(Array *arr, char *element) { +void arr_remove(Array *arr, char *element) +{ // Search for the first occurence of the element and remove it. - // Don't forget to free its memory! + int position = 0; + for (int i = 0; i < arr->count; i++) + { + if (arr->elements[i] == element) + { + position = i; + arr->elements[i] = NULL; + // Don't forget to free its memory! + free(arr->elements[i]); + } + } // Shift over every element after the removed element to the left one position + for (int i = position; i < arr->count; i++) + { + arr->elements[i] = arr->elements[i + 1]; + } // Decrement count by 1 - + arr->count--; } - /***** * Utility function to print an array. *****/ -void arr_print(Array *arr) { +void arr_print(Array *arr) +{ printf("["); - for (int i = 0 ; i < arr->count ; i++) { + for (int i = 0; i < arr->count; i++) + { printf("%s", arr->elements[i]); - if (i != arr->count - 1) { + if (i != arr->count - 1) + { printf(","); } } printf("]\n"); } - #ifndef TESTING int main(void) {