Programming Example Highest GPA Input The program reads

Programming Example: Highest GPA Input The program reads an input file consisting of each student’s GPA, followed by the student’s name. Sample data is: 3. 8 3. 6 3. 9 3. 7 3. 4 3. 9 3. 4 Lisa John Susan Kathy Jason David Jack Data Structures Using C++ 1

Programming Example: Highest GPA (Algorithm) Declare the variables. Open the input file. If the input file does not exist, exit the program. Set the output of the floating-point numbers to a fixed decimal format with a decimal point and trailing zeroes. Also, set the precision to two decimal places. 5. Read the GPA and student name. 6. highest. GPA = GPA; 7. Initialize the stack. 1. 2. 3. 4. Data Structures Using C++ 2

Programming Example: Highest GPA (Algorithm) 8. while (not end of file) { 8. 1 if (GPA > highest. GPA) { 8. 1. 1 destroy. Stack(stack); 8. 1. 2 push(stack, student name); 8. 1. 3 highest. GPA = GPA; } 8. 2 else if(GPA is equal to highest. GPA) push(stack, student name); 8. 3 Read the GPA and student name; } Data Structures Using C++ 3

Programming Example: Highest GPA (Algorithm) 9. Output the highest GPA. 10. Output the names of the students having the highest GPA. Data Structures Using C++ 4

Programming Example: Highest GPA (Sample Run) Input File (Ch 7_Highest. GPAData. txt) 3. 4 3. 2 2. 5 3. 4 3. 8 3. 6 3. 5 3. 8 3. 7 3. 9 3. 8 3. 9 2. 7 3. 9 3. 4 Holt Bolt Colt Tom Ron Mickey Pluto Donald Cindy Dome Andy Fox Minnie Goofy Doc Danny Data Structures Using C++ 5

Programming Example: Highest GPA (Sample Run) Output Highest GPA = 3. 90 The students holding the highest GPA are: Doc Minnie Andy Data Structures Using C++ 6

Empty and Nonempty Linked Stack Empty linked stack Nonempty linked stack Data Structures Using C++ 7

Default Constructor template<class Type> //default constructor linked. Stack. Type<Type>: : linked. Stack. Type() { stack. Top = NULL; } Data Structures Using C++ 8

Destroy Stack template<class Type> void linked. Stack. Type<Type>: : destroy. Stack() { node. Type<Type> *temp; //pointer to delete the node while(stack. Top != NULL) //while there are elements //in the stack { temp = stack. Top; //set temp to point to //the current node stack. Top = stack. Top->link; //advance stack. Top //to the next node delete temp; //deallocate the memory //occupied by temp } }//end destroy. Stack Data Structures Using C++ 9

initialize. Stack and is. Stack. Empty template<class Type> void linked. Stack. Type<Type>: : initialize. Stack() { destroy. Stack(); } template<class Type> bool linked. Stack. Type<Type>: : is. Empty. Stack() { return(stack. Top == NULL); } template<class Type> bool linked. Stack. Type<Type>: : is. Full. Stack() { return false; Data Structures Using C++ 10

Push Stack before the push operation Stack and new. Node Data Structures Using C++ 11

Push Stack after the statement new. Node ->link = stack. Top; executes Stack after the statement stack. Top = new. Node; executes Data Structures Using C++ 12

Return Top Element template<class Type> Type linked. Stack. Type<Type>: : top() { assert(stack. Top != NULL); return stack. Top->info; }//end top Data Structures Using C++ //if the stack is empty, //terminate the program //return the top element 13

Pop Stack before the pop operation Data Structures Using C++ 14

Pop Stack after the statements temp = stack. Top; and stack. Top = stack. Top->link; execute Stack after the statement delete temp; executes Data Structures Using C++ 15

Nonrecursive Algorithm to Print Linked List current = first; while(current != NULL) { stack. push(current); current = current->link; } Data Structures Using C++ //Line 1 //Line 2 //Line 3 //Line 4 16

List After Execution of Statement current = first; Data Structures Using C++ 17

Repeated Execution of: stack. push(current); current = current->link; Data Structures Using C++ 18

Operations on a stack Object Data Structures Using C++ 19

Chapter Summary �Stack Data Structure �Last In First Out (LIFO) �Stacks Implemented as Arrays �Stacks Implemented as Linked Lists �Nonrecursive Algorithm to Print Linked List Data Structures Using C++ 20