week-13x
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The document describes a C program to create a sorted linked list from an unsorted list of numbers. It includes functions to insert nodes in sorted order, print the list, and count the number of nodes. The main function accepts user input to build the initial list, then calls the insert_sort function to sort it and other functions to output the sorted list and count of nodes.
week-13x
- 1. /* Write a program for creation of sorted list from a given list of numbers */ #include <stdio.h> #include <stdlib.h> #define NULL 0 struct linked_list { int number; struct linked_list *next; }; typedef struct linked_list node; main () { int n; node *head = NULL; void print(node *p); node *insert_Sort(node *p, int n); printf("Input the list of numbers.n"); printf("At end, type -999.n");
- 2. scanf("%d",&n); while(n != -999) { if(head == NULL) /* create 'base' node */ { head = (node *)malloc(sizeof(node)); head ->number = n; head->next = NULL; } else /* insert next item */ { head = insert_sort(head,n); } scanf("%d", &n); } printf("n"); print(head); print("n"); } node *insert_sort(node *list, int x) {
- 3. node *p1, *p2, *p; p1 = NULL; p2 = list; /* p2 points to first node */ for( ; p2->number < x ; p2 = p2->next) { p1 = p2; if(p2->next == NULL) { p2 = p2->next; /* p2 set to NULL */ break; /* insert new node at end */ } } /* key node found */ p = (node *)malloc(sizeof(node)); /* space for new node */ p->number = x; /* place value in the new node */ p->next = p2; /* link new node to key node */ if (p1 == NULL) list = p; /* new node becomes the first node */ else p1->next = p; /* new node inserted after 1st node */ return (list);
- 4. } void print(node *list) { if (list == NULL) printf("NULL"); else { printf("%d-->",list->number); print(list->next); } return; } Output Input the list of number. At end, type -999. 80 70 50 40 60 -999 40-->50-->60-->70-->80 -->NULL Input the list of number. At end, type -999. 40 70 50 60 80 -999 40-->50-->60-->70-->80-->NULL
- 5. /* Write a function for inserting an item into a linked list */ node *insert(node *head) { node *find(node *p, int a); node *new; /* pointer to new node */ node *n1; /* pointer to node preceding key node */ int key; int x; /* new item (number) to be inserted */ printf("Value of new item?"); scanf("%d", &x); printf("Value of key item ? (type -999 if last) "); scanf("%d", &key); if(head->number == key) /* new node is first */ { new = (node *)malloc(size of(node));
- 6. new->number = x; new->next = head; head = new; } else /* find key node and insert new node */ { /* before the key node */ n1 = find(head, key); /* find key node */ if(n1 == NULL) printf("n key is not found n"); else /* insert new node */ { new = (node *)malloc(sizeof(node)); new->number = x; new->next = n1->next; n1->next = new; } } return(head); } node *find(node *lists, int key) { if(list->next->number == key) /* key found */ return(list);
- 7. else if(list->next->next == NULL) /* end */ return(NULL); else find(list->next, key); }
- 8. /* Write a function for deleting an item from linked list */ node *delete(node *head) { node *find(node *p, int a); int key; /* item to be deleted */ node *n1; /* pointer to node preceding key node */ node *p; /* temporary pointer */ printf("n What is the item (number) to be deleted?"); scanf("%d", &key); if(head->number == key) /* first node to be deleted) */ { p = head->next; /* pointer to 2nd node in list */ free(head); /* release space of key node */ head = p; /* make head to point to 1st node */
- 9. } else { n1 = find(head, key); if(n1 == NULL) printf("n key not found n"); else /* delete key node */ { p = n1->next->next; /* pointer to the node following the keynode */ free(n1->next); /* free key node */ n1->next = p; /* establish link */ } } return(head); } /* USE FUNCTION find() HERE */
- 10. /* Write a program to create a linear linked list interactively and print out the list and the total number of items in the list. */ #include <stdio.h> #include <stdlib.h> #define NULL 0 struct linked_list { int number; struct linked_list *next; }; typedef struct linked_list node; /* node type defined */ main()
- 11. { node *head; void create(node *p); int count(node *p); void print(node *p); head = (node *)malloc(sizeof(node)); create(head); printf("n"); printf(head); printf("n"); printf("nNumber of items = %d n", count(head)); } void create(node *list) { printf("Input a numbern"); printf("(type -999 at end): "); scanf("%d", &list -> number); /* create current node */ if(list->number == -999) { list->next = NULL; } else /*create next node */
- 12. { list->next = (node *)malloc(sizeof(node)); create(list->next); */ Recursion occurs */ } return; } void print(node *list) { if(list->next != NULL) { printf("%d-->",list ->number); /* print current item */ if(list->next->next == NULL) printf("%d", list->next->number); print(list->next); /* move to next item */ } return; } int count(node *list) { if(list->next == NULL) return (0);
- 13. else return(1+ count(list->next)); } Output Input a number (type -999 to end); 60 Input a number (type -999 to end); 20 Input a number (type -999 to end); 10 Input a number (type -999 to end); 40 Input a number (type -999 to end); 30 Input a number (type -999 to end); 50 Input a number (type -999 to end); -999 60 -->20 -->10 -->40 -->30 -->50 --> -999 Number of items = 6