ADT Linked List

/*  Author:     Fabiola C. Villanueva
    Project:    Linked List
    Time:       July 9, 2023 (5:00pm)
    End:        July 9, 2023 (7:42pm)
*/

#include <stdio.h>
#include <stdlib.h>
#define MENU 5

typedef char STRING[50];

//structure definitions
typedef struct node {
    int data;
    struct node *next;
} NodeType, *NodePtr;

//function prototypes
void insertSorted (NodePtr *list);
int searchData (NodePtr list);
void deleteAllData (NodePtr *list);
void display (NodePtr list);

int main() {
    system("CLS");

    NodePtr head = NULL;
    int i, item, choice, pos;
    STRING menu[MENU] = {  "Exit",
                            "Insert Sorted",
                            "Search Data",
                            "Delete All",
                            "Display List" };

    do {
        printf("MENU\nKindly select a number:\n\n");
        for (i = 0; i < MENU; ++i) {
            printf("    [%d] %s\n", i, menu[i]);
        }
        printf("\nChoice: ");
        scanf("%d", &choice);

        system("CLS");

        switch (choice) {
            case 0:
                printf("\n\"EXIT\"\n\n");
                display(head);
                printf("\n\nTerminating program...");

                break;

            case 1:
                printf("\n\"INSERT SORTED\"\n\n");
                display(head);
                insertSorted (&head);
                printf("\n");
                display(head);

                break;

            case 2:
                printf("\n\"SEARCH DATA\"\n\n");
                display(head);
                pos = searchData (head);
                printf("Data is at position = [%d]\n\n", pos);
                display(head);

                break;

            case 3:
                printf("\n\"DELETE ALL\"\n\n");
                display(head);
                deleteAllData (&head);
                display(head);

                break;

            case 4:
                printf("\n\"DISPLAY LIST\"\n\n");
                display(head);

                break;
        }

        printf("\n\n");
        system("PAUSE");
        system("CLS");

    } while (choice != 0);

    printf("\n");
    return 0;
}

//function defenitions
void insertSorted (NodePtr *list) {                             //a list from main will never enter this function unsorted
    NodePtr temp = (NodePtr) malloc (sizeof(NodeType));         //make temp node
    NodePtr *trav;
    int item;

    printf("\nEnter item to insert: ");         //user input for data to insert
    scanf("%d", &item);

    if (temp != NULL) {                         //if temp is allocated
        temp->data = item;                      //populate temp data
        temp->next = NULL;                      //pre assign to NULL, overwrite later
    }                                           //traverse until in right position

    for (trav = list; (*trav) != NULL && (*trav)->data < temp->data; trav = &(*trav)->next) {}

    temp->next = (*trav);                       //exits loop once item is in right position
    (*trav) = temp;                             //insert the temp node in place
}

int searchData (NodePtr list) {     //return pos, if pos not found return -1
    NodePtr trav;
    int i, item, ret = -1;

    printf("\nEnter data to search: ");
    scanf("%d", &item);

    for (trav = list, i = 0; trav != NULL && trav->data != item; trav = trav->next, ++i) {
        if (trav->data == item) {       //traverse and checking if item is found,
            ret = i;                    //loop automatically exits then assigns i to ret
        }
    }                                   //if not found, ret stays -1

    return ret;
}

void deleteAllData (NodePtr *list) {        //delete all occurences of user input item
    NodePtr *trav, temp;
    int item;

    printf("\nEnter item to delete: ");
    scanf("%d", &item);

    for (trav = list; (*trav) != NULL;) {
        if ((*trav)->data == item) {        //if data in a node is found,
            temp = (*trav);                 //temp will get whole node to delete
            (*trav) = temp->next;           //update for conditon when item found
            free(temp);                     //deletion of temp
        } else {
            trav = &(*trav)->next;          //update to continue if not item
        }
    }
}

void display (NodePtr list) {       //"pass by copy of list"; accessing via single pointer direct to first node
    printf("List = { ");
    for (; list != NULL; list = list->next) {
        printf("[%d]", list->data);
        if (list->next != NULL) {
            printf(" -> ");
        }
    }
    printf(" }");
}