davinci-001_08 (Autopilot) list.c

Mean logprob: -0.3536469096106608 (70.21%)
Legend: 0%100%

#include <stdio.h> 
#include <stdlib.h>
#include <getopt.h>
#include <string.h>
#include "list.h"

#ifdef UNIT_TESTING
/* Redirect printf to a function in the test application so it's possible to
 * test the standard output. You can ignore this; it's not relevant to the
 * assignment. */
#ifdef printf
#undef printf
#endif /* printf */
extern int test_printf(const char *format,...);
#define printf test_printf
#endif

#define MAX_ITEM_PRINT_LEN 100

// Note: All list_ functions return a status code EXIT_FAILURE or EXIT_SUCCESS
// to indicate whether the operation was successful or not.

// Members of the node struct:
// char* item_name, float price, int quantity, node *next

// create a new list
int list_init(node **head) {
    *head = NULL;
    return EXIT_SUCCESS;
}

// print a single list item to an externally allocated string
// This should be in the format of:
// "quantity * item_name @ $price ea", where item_name is a string and 
// price is a float formatted with 2 decimal places.
int list_item_to_string(node *head, char *str) {
    int result = EXIT_SUCCESS;

    if (head == NULL) {
        strcpy(str, "The list is empty.");
    } else {
        int item_name_len = strlen(head->item_name);
        int price_len = snprintf(NULL, 0, "%.2f", head->price);
        int quantity_len = snprintf(NULL, 0, "%d", head->quantity);
        int total_len = item_name_len + price_len + quantity_len + 12;

        if (total_len > MAX_ITEM_PRINT_LEN) {
            result = EXIT_FAILURE;
            strcpy(str, "The item name is too long.");
        } else {
            int printed = snprintf(str, total_len, "%d * %s @ $%.2f ea", head->quantity, head->item_name, head->price);

            if (printed!= total_len) {
                result = EXIT_FAILURE;
                strcpy(str, "The string was not filled completely.");
            }
        }
    }

    return result;
}

// print the list to stdout
// This should be in the format of:
// "pos: quantity * item_name @ $price ea", where 
//   pos is the position of the item in the list, 
//   item_name is the item_name of the item and 
//   price is the float price of the item formatted with 2 decimal places.
// For example:
// """1: 3 * banana @ $1.00 ea
// 2: 2 * orange @ $2.00 ea
// 3: 4 * apple @ $3.00 ea
// """
// It should return a newline character at the end of each item. 
// It should not have a leading newline character.
int list_print(node *head) {
    int result = EXIT_SUCCESS;

    if (head == NULL) {
        printf("The list is empty.\n");
    } else {
        node *current = head;
        int printed = 0;

        while (current!= NULL) {
            char str[MAX_ITEM_PRINT_LEN];
            int item_name_len = strlen(current->item_name);
            int price_len = snprintf(NULL, 0, "%.2f", current->price);
            int quantity_len = snprintf(NULL, 0, "%d", current->quantity);
            int total_len = item_name_len + price_len + quantity_len + 12;

            if (total_len > MAX_ITEM_PRINT_LEN) {
                result = EXIT_FAILURE;
                break;
            } else {
                int printed = snprintf(str, total_len, "%d * %s @ $%.2f ea", current->quantity, current->item_name, current->price);

                if (printed!= total_len) {
                    result = EXIT_FAILURE;
                    break;
                }

                printf("%s\n", str);
            }

            current = current->next;
        }
    }

    return result;
}

// add a new item (name, price, quantity) to the list at position pos, 
//   such that the added item is the item at position pos
// For example:
// If the list is:
// 1: 3 * banana @ $1.00 ea
// 2: 2 * orange @ $2.00 ea
// and you call list_add_item_at_pos(&head, "apple", 3.0, 4, 2)
// the list should be:
// 1: 3 * banana @ $1.00 ea
// 2: 4 * apple @ $3.00 ea
// 3: 2 * orange @ $2.00 ea
int list_add_item_at_pos(node **head, char *item_name, float price, int quantity, unsigned int pos) {
    int result = EXIT_SUCCESS;
    node *new_node = NULL;

    if (pos == 0) {
        new_node = malloc(sizeof(node));
        new_node->next = *head;
        *head = new_node;
    } else {
        node *current = *head;
        node *prev = NULL;
        int i = 0;

        while (i < pos) {
            prev = current;
            current = current->next;
            i++;
        }

        new_node = malloc(sizeof(node));
        new_node->next = current;
        prev->next = new_node;
    }

    if (new_node!= NULL) {
        new_node->item_name = (char *)malloc(strlen(item_name) + 1);
        strcpy(new_node->item_name, item_name);
        new_node->price = price;
        new_node->quantity = quantity;
    } else {
        result = EXIT_FAILURE;
    }

    return result;
}

// update the item at position pos
int list_update_item_at_pos(node **head, char *item_name, float price, int quantity, unsigned int pos) {
    int result = EXIT_SUCCESS;
    node *current = *head;
    node *prev = NULL;
    int i = 0;

    if (pos == 0) {
        current->item_name = (char *)malloc(strlen(item_name) + 1);
        strcpy(current->item_name, item_name);
        current->price = price;
        current->quantity = quantity;
    } else {
        while (i < pos) {
            prev = current;
            current = current->next;
            i++;
        }

        current->item_name = (char *)malloc(strlen(item_name) + 1);
        strcpy(current->item_name, item_name);
        current->price = price;
        current->quantity = quantity;
    }

    return result;
}

// remove the item at position pos
int list_remove_item_at_pos(node **head, int pos) {
    int result = EXIT_SUCCESS;
    node *prev = NULL;
    node *current = *head;
    int i = 0;

    if (pos == 0) {
        *head = current->next;
    } else {
        while (i < pos) {
            prev = current;
            current = current->next;
            i++;
        }

        prev->next = current->next;
    }

    free(current);

    return result;
}

// swap the item at position pos1 with the item at position pos2
int list_swap_item_positions(node **head, int pos1, int pos2) {
    int result = EXIT_SUCCESS;
    node *pos1_node = NULL;
    node *pos2_node = NULL;
    node *prev_to_pos1 = NULL;
    node *prev_to_pos2 = NULL;
    int i = 0;

    if (pos1 == pos2) {
        return result;
    }

    if (pos1 == 0) {
        pos1_node = *head;
    } else {
        prev_to_pos1 = *head;

        while (i < pos1) {
            prev_to_pos1 = pos1_node;
            pos1_node = pos1_node->next;
            i++;
        }
    }

    if (pos2 == 0) {
        pos2_node = *head;
    } else {
        prev_to_pos2 = *head;

        while (i < pos2) {
            prev_to_pos2 = pos2_node;
            pos2_node = pos2_node->next;
            i++;
        }
    }

    if (pos1_node == NULL || pos2_node == NULL) {
        result = EXIT_FAILURE;
    } else {
        if (pos1_node == *head) {
            *head = pos2_node;
        } else {
            prev_to_pos1->next = pos2_node;
        }

        if (pos2_node == *head) {
            *head = pos1_node;
        } else {
            prev_to_pos2->next = pos1_node;
        }

        node *temp = pos1_node->next;
        pos1_node->next = pos2_node->next;
        pos2_node->next = temp;
    }

    return result;
}

// find the item position with the highest single price
int list_find_highest_price_item_position(node *head, int *pos) {
    int result = EXIT_SUCCESS;
    float highest_price = 0.0;
    node *current = head;
    int i = 0;

    while (current!= NULL) {
        if (current->price > highest_price) {
            highest_price = current->price;
            *pos = i;
        }

        i++;
        current = current->next;
    }

    if (highest_price == 0.0) {
        result = EXIT_FAILURE;
    }

    return result;
}

// calculate the total cost of the list (sum of all prices * quantities)
int list_cost_sum(node *head, float *total) {
    int result = EXIT_SUCCESS;
    node *current = head;
    *total = 0.0;

    while (current!= NULL) {
        *total += (current->price * current->quantity);
        current = current->next;
    }

    return result;
}

// save the list to file filename
// the file should be in the following format:
// item_name,price,quantity\n 
//   (one item per line, separated by commas, and newline at the end)
int list_save(node *head, char *filename) {
    int result = EXIT_SUCCESS;
    FILE *file = fopen(filename, "w");

    if (file == NULL) {
        result = EXIT_FAILURE;
    } else {
        node *current = head;

        while (current!= NULL) {
            fprintf(file, "%s,%.2f,%d\n", current->item_name, current->price, current->quantity);
            current = current->next;
        }

        fclose(file);
    }

    return result;
}

// load the list from file filename
// the file should be in the following format:
// item_name,price,quantity\n 
//   (one item per line, separated by commas, and newline at the end)
// the loaded values are added to the end of the list
int list_load(node **head, char *filename) {
    int result = EXIT_SUCCESS;
    node *current = NULL;
    node *next = NULL;
    FILE *file = fopen(filename, "r");

    if (file == NULL) {
        result = EXIT_FAILURE;
    } else {
        char buffer[128];
        while (fgets(buffer, 128, file)) {
            int pos = 0;
            int item_name_len = strlen(buffer);
            buffer[item_name_len - 1] = 0;

            while (buffer[pos]!= ',') {
                pos++;
            }

            char *item_name = (char *)malloc(pos + 1);
            strncpy(item_name, buffer, pos);
            item_name[pos] = 0;
            float price = atof(buffer + pos + 1);
            int quantity = atoi(buffer + pos + 5);

            next = malloc(sizeof(node));
            next->item_name = item_name;
            next->price = price;
            next->quantity = quantity;
            next->next = NULL;

            if (current == NULL) {
                *head = next;
            } else {
                current->next = next;
            }

            current = next;
        }

        fclose(file);
    }

    return result;
}

// de-duplicate the list by combining items with the same name 
//    by adding their quantities
// The order of the returned list is undefined and may be in any order
int list_deduplicate(node **head) {
    int result = EXIT_SUCCESS;
    node *current = *head;
    node *prev = NULL;
    node *next = NULL;

    while (current!= NULL) {
        next = current->next;

        while (next!= NULL) {
            if (strcmp(current->item_name, next->item_name) == 0) {
                current->quantity += next->quantity;
                current->price += next->price;
                free(next);
                next = current->next;
            } else {
                prev = next;
                next = next->next;
            }
        }

        current = current->next;
    }

    return result;
}