FINAL EXAMINATION *** JANUARY 30, minutes [6,600 seconds]

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1 CMPE-231 DATA STRUCTURES Computer Engineering Department, EMU FINAL EXAMINATION *** JANUARY 30, minutes [6,600 seconds] Results KEY COPY 1 / 20 2 / 20 3 / 20 4 / 20 5 / 25 Total / 105 Name, Surname void ID # void Group # 1 2 *** circle Your group number [KD] [MG] TASK 1 Consider the following simplified C implementation of a STACK using SINGLY LINKED LIST structure. Assume that we perform only PUSH operation on stack some statements in the corresponding function push( ) are already written. You have to finish the definition of the push( ) function, i.e. to write the remaining statements. Please, note that ONLY 3(three) statements should be written (not more, or not less). #include <stdio.h> #include <stdlib.h> typedef struct node int data; struct node *next; STACKNODE; void push(int, STACKNODE **); // declaration of the function push() int main(void) STACKNODE *stack=null; int element; do printf( \ninput the integer value: ); scanf( %d,&element); push(element, &stack); while (element); KEY COPY CMPE-231 Examination 1

2 return 0; // definition of the function push() starts here void push(int element, STACKNODE **stack) STACKNODE *newnode; // allocation of the memory takes place newnode=(stacknode *)malloc(sizeof(stacknode)); if(newnode==null) puts( Memory allocation failed ); exit(1); newnode->data = element; // statement 1 newnode->next = (*stack); // statement 2 (*stack) = newnode; // statement 3 TASK 2 [10 points] Determine (draw) a BINARY TREE whose INORDER traversal is * 3 / and whose PREORDER traversal is - * / KEY COPY CMPE-231 Examination 2

3 TASK 3 Consider the following BINARY TREE: What are the results of PREORDER, POSTORDER and INORDER traversals of the shown tree structure? PREORDER POSTORDER INORDER A B D G J C E H K I L F J G D B K H L I E F C A D J G B A H K E I L C F TASK 4 [10 points] Consider the following arithmetic expression: 5+(4+7)* (9-3)/2+1. Show (draw) a BINARY TREE that represents this expression. Is it a STRICTLY BINARY TREE? YES, it is strictly binary tree KEY COPY CMPE-231 Examination 3

4 TASK 5 Consider the following function that concatenates two lists; that is, it appends the CIRCULAR LIST pointed to by list2 to the end of the CIRCULAR LIST pointed to by list1. You have to write last 4 (four) statements that perform required action. NOTE: Assume that in a circular linked list the external pointer is used to point to the last node in the list. void concat(nodeptr *list1, NODEPTR *list2) NODEPTR p; if( * list2 == NULL) if(* list1 == NULL) * list1 = * list2; p = (*list1) -> next; // statement 1 (*list1) -> next = (*list2) -> next; // statement 2 (*list2) -> next = p; // statement 3 *list1 = *list2; ; // statement 4 Declaration part of the program that calls the above given function looks as follows: struct node int data; struct node * next; ; typedef struct node * NODEPTR; KEY COPY CMPE-231 Examination 4

5 TASK 6 [20 points] Consider a fragment of the following SINGLY LINKED LIST structure: Assume that nodes A, B, C, D, E, etc. are already allocated at the following memory addresses: address of the node A 100 address of the node B 108 address of the node C 116 address of the node D 124 address of the node E 132 Considering the code shown below, provide your answers to the following questions: 1) first, we call function fun( ) and pass address of the node C as an argument. What value function fun( ) returns? 2) after a call to fun( ) we call function fun1( ) and pass the address of the node B as an argument to it. What value function fun( ) returns in this case? typedef struct node int info; struct node * next; SLList; SLList * fun(sllist * a) SLList * b = NULL; if(a!= NULL) b = a -> next; free(a); return b; KEY COPY CMPE-231 Examination 5

6 void fun1(sllist * a) if(a!= NULL && a -> next!= NULL) a -> next = fun(a -> next); 1) function fun( ) returns the address of the node D (i.e. 124) 2) function fun( ) returns the address of the node D (i.e. 124) again TASK 7 Consider the following CIRCULAR DOUBLY LINKED LIST structure: Write C function sum( ) that traverses the whole structure from RIGHT to LEFT counting the sum of node values (i.e ). Function is called from the function main( ) (see program s fragment below) Declaration part of the program looks as follows: typedef struct node * NODEPTR; struct node int data; struct node * prev; struct node * next; ; int sum(nodeptr); // prototype of the function sum( ) KEY COPY CMPE-231 Examination 6

7 The following code is already prepared in advance use it and don t change it: int main(void) Write the argument in the function s call NODEPTR header; // we assume that doubly LL is already created and // values of all list s nodes are set properly... // DON T DEAL WITH THIS PART OF THE PROGRAM! printf( the sum of elements is %d\n, sum( header -> prev )); return 0; int sum(nodeptr a) // definition of the function sum( ) NODEPTR temp; int count = a -> data; temp = a -> prev; while(temp!= a) count + = temp -> data; temp = temp -> prev; return count; Write Your code inside the box TEXT OUTSIDE BOX IS NOT CHECKED! KEY COPY CMPE-231 Examination 7