This program is based on Examples: 3.15 - 3.19 - book Driver program to demonstrate hashing using collision resolution by chaining. Write the definition of the linkedListKeepLast function. The purpose of the function is to create a new linked list containing the last node in each linked list in the hash table beginning with the first linked list. The rest of the nodes are to be displayed to the screen, then returned to the heap. Example: If the user enters the following keys: 201, 102, 233, 567, 456, 654, 465, 645, quit list at index 0 is empty list at index 1 is not empty: 201 102 567 list at index 2 is not empty: 233 list at index 3 is empty list at index 4 is not empty: 456 654 465 645 Deleted nodes: --> at index 0: --> at index 1: 201 102 --> at index 2: --> at index 3: --> at index 4: 456 654 465 The final linked list contains: 567 233 645 Written by: */ #include  #include  // malloc(), free(), exit() #include  #define NUMPOINTERS 5 typedef struct node STUDENTREC; struct node { char id[10]; struct node *next; }; // Function Declarations int hash(char id[]); STUDENTREC *insert(char id[], STUDENTREC *student_body[], int hashval); void traverse(STUDENTREC *student_body[]); void displayLL(STUDENTREC *list, char *description); STUDENTREC *linkedListKeepLast(STUDENTREC *student_body[]); int main (void) { STUDENTREC *student_body[NUMPOINTERS] = {NULL}; STUDENTREC *person; STUDENTREC *endList; char id[10]; int hashval; printf(" ~*~ Hashing using collision resolution by chaining ~*~ "); printf("\t Enter Student ID (or quit): "); scanf("%s", id); while(strcmp(id, "quit")) { hashval = hash(id); person = insert(id, student_body, hashval); if (person) // not NULL => duplicate { printf("Duplicate record! "); } printf("\t Enter Student ID (or quit): "); scanf("%s", id); } traverse(student_body); endList = linkedListKeepLast(student_body); displayLL(endList, "New List"); traverse(student_body); return 0; } /* The purpose of the function is to create a new linked list containing the last node in each linked list in the hash table beginning with the first linked list. The rest of the nodes are to be displayed to the screen, then returned to the heap. */ STUDENTREC *linkedListKeepLast(STUDENTREC *student_body[]) { STUDENTREC *newList = NULL; /* ********************************************************* Write your code here Get the job done without calling other linked list functions ********************************************************* */ return newList; } /*************************************************** Hash Student ID by summing the cubes of the ASCII value of characters and then take the modulo of this sum. */ int hash(char id[]) { long sum = 0; while (*id) // != '\0' { sum += *id * *id * *id; id++; } return sum % NUMPOINTERS; } /*************************************************** Insert a new Social Security number into the array of student records, at index equal to hashvalue */ STUDENTREC *insert(char id[], STUDENTREC *student_body[], int hashval) { STUDENTREC **mover; // Use ** to write elegant code mover = &student_body[hashval]; while (*mover) { if (strcmp(id,(*mover)->id) == 0) return *mover; mover = &((*mover)->next); } if ((*mover = (STUDENTREC *) malloc(sizeof(STUDENTREC))) == NULL) { printf("Malloc error in insert! "); exit(1); } strcpy((*mover)->id, id); (*mover)->next = NULL; // set the link of the new node to NULL printf("%s has been placed in the list at location %d. ", (*mover)->id, hashval); return NULL; } /*************************************************** Traversing the lists in a hash table */ void traverse(STUDENTREC *student_body[]) { int i; // STUDENTREC **mover; // Use ** for fun and practice // not needed for traverse for (i = 0; i < NUMPOINTERS; i++) { printf("Contents of list %2d ", i); printf("-------------------- "); // for (mover = &student_body[i]; *mover; mover = &(*mover)->next) // { // &((*mover)->next) // printf("%s ", (*mover)->ss); // } displayLL(student_body[i], NULL); printf(" "); } } /*************************************************** Traversing a linked list */ void displayLL(STUDENTREC *list, char *description) { if (list) // != NULL { if (description) // != NULL { printf ("%s ", description); printf("-------------------- "); } STUDENTREC **mover; // Use ** for fun and practice // not needed for traverse for (mover = &list; *mover; mover = &(*mover)->next) { // &((*mover)->next) printf("%s ", (*mover)->id); } } else printf ("Empty!"); printf(" "); } /* ~*~ Hashing using collision resolution by chaining ~*~ Enter Student ID (or quit): 201 201 has been placed in the list at location 1. Enter Student ID (or quit): 102 102 has been placed in the list at location 1. Enter Student ID (or quit): 233 233 has been placed in the list at location 2. Enter Student ID (or quit): 567 567 has been placed in the list at location 1. Enter Student ID (or quit): 456 456 has been placed in the list at location 4. Enter Student ID (or quit): 654 654 has been placed in the list at location 4. Enter Student ID (or quit): 465 465 has been placed in the list at location 4. Enter Student ID (or quit): 645 645 has been placed in the list at location 4. Enter Student ID (or quit): quit Contents of list 0 -------------------- Empty! Contents of list 1 -------------------- 201 102 567 Contents of list 2 -------------------- 233 Contents of list 3 -------------------- Empty! Contents of list 4 -------------------- 456 654 465 645 Deleted nodes: --> at index 0: --> at index 1: 201 102 --> at index 2: --> at index 3: --> at index 4: 456 654 465 New List -------------------- 567 233 645 Contents of list 0 -------------------- Empty! Contents of list 1 -------------------- Empty! Contents of list 2 -------------------- Empty! Contents of list 3 -------------------- Empty! Contents of list 4 -------------------- Empty! */