Stack Data Structures (Arabic) PDF

# علوم الحاسب ## الفرقة الثانية ### Session 3 ### هياكل البيانات ## Data Structures ## Q.1. Define pointer. A pointer is a variable which can store the address of another variable. A pointer is also a variable, so it has its own memory address. **Memory address:** 1020 1024 1032 - 100 integer - 1...

# علوم الحاسب ## الفرقة الثانية ### Session 3 ### هياكل البيانات ## Data Structures ## Q.1. Define pointer. A pointer is a variable which can store the address of another variable. A pointer is also a variable, so it has its own memory address. **Memory address:** 1020 1024 1032 - 100 integer - 1024 pointer **To define pointers** - type\* pointer\_name; - type \*pointer\_name; **Note:** type is the type of data pointed to (int, char, double) ## Q.2. Using the next memory address, write output for the following code. **Memory address:** 1020 1024 1032 - 88 - 100 - 1024 - ... ```c++ int a = 100; int *p = &a; cout << a << endl; cout << &a << endl; cout << p << endl; cout << *p << endl; cout << &p << endl; ``` Output: - 100 - 1024 - 1024 - 100 - 1032 ## Q.3. Write output for the following code. ```c++ #include <iostream> #include <conio.h> using namespace std; void main() { int *p, x; p = &x; cout << "Enter a number \n"; cin >> x; cout << "\n THE VALUE OF X(THROUGH POINTER) IS " << *p; cout << "\n THE VALUE OF X IS " << X; cout << "\n THE VALUE OF p " << p; *p = 101; cout << "\n THE VALUE OF X(THROUGH POINTER) IS " << *p; cout << "\n THE VALUE OF X IS " << X; cout << "\n THE VALUE OF p " << p <<endl; _getch(); } ``` **Enter a number:** 100 **Output:** - THE VALUE OF X(THROUGH POINTER) IS 100 - THE VALUE OF X IS 100 - THE VALUE OF p 00000075467AFBE4 - THE VALUE OF X(THROUGH POINTER) IS 101 - THE VALUE OF X IS 101 - THE VALUE OF p 00000075467AFBE4 ## Q.4. What is Structure? Give an example for structure. A structure is a collection of data items (fields) or variables of different data types that are referenced under the same name. A structure provides convenient means of keeping related information together. ```c++ #include <iostream> #include <conio.h> using namespace std; struct emp { char name[25]; int age; float salary; }; void main() { emp e; cout << "Enter the name, age and salary \n"; cin.get(e.name, 25); cin >> e.age >> e.salary; cout << "\n NAME IS " << e.name << "\n AGE IS " << e.age << "\n SALARY IS " << e.salary << endl; _getch(); } ``` **Enter the name, age and salary:** - Ali - 25 - 5000 **Output:** - NAME IS Ali - AGE IS 25 - SALARY IS 5000 ## Q.5. What is stack? A stack is an Abstract Data Type (ADT), it behaves like a real-world stack, for example - a deck of cards or a pile of plates, etc. - Stack ADT allows all data operations at one end only. [True] - At any given time, we can only access the top element of a stack. [True] - Stack works as LIFO (Last-in-first-out). - The insertion operation is called PUSH. - Removal operation is called POP. - push() Pushing (storing) an element on the stack. - pop() Removing (accessing) an element from the stack. - Peek() get the top data element of the stack, without removing it. - isFull() check if stack is full. - isEmpty() check if stack is empty. - A stack can be implemented by means of Array, Structure, Pointer, and Linked List. - Stack can either be a fixed size (array) one or it may have a sense of dynamic resizing. ## Stack Implementation ```c++ #include <iostream> using namespace std; int stack[5]; int top = 0; void push(int); int pop(); void traverse(); int is_empt(); int top_element(); int main() { int element, choice; for (;;) { cout << "Stack Operations.\n"; cout << "1. Insert into stack (Push operation).\n"; cout << "2. Delete from stack (Pop operation).\n"; cout << "3. Print top element of stack.\n"; cout << "4. Check if stack is empty.\n"; cout << "5. Traverse stack.\n"; cout << "6. Exit.\n"; cout << "Enter your choice.\n"; cin >> choice; switch (choice) { case 1: if (top == 5) { cout << "Error: Overflow\n\n"; } else { cout << "Enter a value to insert.\n"; cin >> element; push(element); } break; case 2: if (top == 0) cout << "Error: Underflow.\n\n"; else { element = pop(); cout << "Element removed from the stack is " << element << "\n"; } break; case 3: if (!is_empt()) { element = top_element(); cout << "Element at the top of the stack is " << element; } else cout << "The stack is empty.\n\n"; break; case 4: if (is_empt()) cout << "The stack is empty.\n\n"; else cout << "The stack isn't empty.\n\n"; break; case 5: traverse(); break; case 6: exit(0); } } } void push(int value) { stack[top] = value; top++; } int pop() { top--; return stack[top]; } int top_element() { return stack[top - 1]; } int is_empt() { if (top == 0) return 1; else return 0; } void traverse() { int d; if (top == 0) { cout << "The stack is empty.\n\n"; return; } cout << "There are" << top << "elements in the stack.\n"; for (d = top - 1; d >= 0; d--) cout << "\n" << stack[d]; } ``` ## Three applications of stacks: - Expression evaluation. - Backtracking (game playing, finding paths, exhaustive searching) - Memory management, run-time environment for nested language features.