Chương trình C++ triển khai ngăn xếp (Stack) bằng mảng

Stack (ngăn xếp) tuân theo LIFO. Triển khai bằng mảng tĩnh kích thước cố định.

Ví dụ

#include <iostream>
using namespace std;

int stack[100], n = 100, top = -1;

void push(int val) {
    if (top >= n - 1)
        cout << "Stack Overflow" << endl;
    else {
        top++;
        stack[top] = val;
    }
}

void pop() {
    if (top <= -1)
        cout << "Stack Underflow" << endl;
    else {
        cout << "The popped element is " << stack[top] << endl;
        top--;
    }
}

void display() {
    if (top >= 0) {
        cout << "Stack elements are: ";
        for (int i = top; i >= 0; i--)
            cout << stack[i] << " ";
        cout << endl;
    } else
        cout << "Stack is empty";
}

int main() {
    int ch, val;
    cout << "1) Push in stack" << endl;
    cout << "2) Pop from stack" << endl;
    cout << "3) Display stack" << endl;
    cout << "4) Exit" << endl;
    do {
        cout << "Enter choice: " << endl;
        cin >> ch;
        switch(ch) {
            case 1: {
                cout << "Enter value to be pushed: " << endl;
                cin >> val;
                push(val);
                break;
            }
            case 2: {
                pop();
                break;
            }
            case 3: {
                display();
                break;
            }
            case 4: {
                cout << "Exit" << endl;
                break;
            }
            default: {
                cout << "Invalid Choice" << endl;
            }
        }
    } while(ch != 4);
    return 0;
}

Kết quả

1) Push in stack
2) Pop from stack
3) Display stack
4) Exit
Enter choice: 1
Enter value to be pushed: 2
Enter choice: 1
Enter value to be pushed: 6
Enter choice: 1
Enter value to be pushed: 8
Enter choice: 1
Enter value to be pushed: 7
Enter choice: 2
The popped element is 7
Enter choice: 3
Stack elements are: 8 6 2
Enter choice: 5
Invalid Choice
Enter choice: 4
Exit

Hàm push()

Kiểm tra tràn (top >= n-1). Tăng top và gán giá trị.

void push(int val) {
    if (top >= n - 1)
        cout << "Stack Overflow" << endl;
    else {
        top++;
        stack[top] = val;
    }
}

Hàm pop()

Kiểm tra rỗng (top <= -1). In stack[top] và giảm top.

void pop() {
    if (top <= -1)
        cout << "Stack Underflow" << endl;
    else {
        cout << "The popped element is " << stack[top] << endl;
        top--;
    }
}

Hàm display()

Duyệt từ top xuống 0 bằng vòng lặp for. Nếu rỗng in thông báo.

void display() {
    if (top >= 0) {
        cout << "Stack elements are: ";
        for (int i = top; i >= 0; i--)
            cout << stack[i] << " ";
        cout << endl;
    } else
        cout << "Stack is empty";
}

Hàm main() - Menu

int main() {
    int ch, val;
    cout << "1) Push in stack" << endl;
    cout << "2) Pop from stack" << endl;
    cout << "3) Display stack" << endl;
    cout << "4) Exit" << endl;
    do {
        cout << "Enter choice: " << endl;
        cin >> ch;
        switch(ch) {
            case 1: {
                cout << "Enter value to be pushed: " << endl;
                cin >> val;
                push(val);
                break;
            }
            case 2: pop(); break;
            case 3: display(); break;
            case 4: cout << "Exit" << endl; break;
            default: cout << "Invalid Choice" << endl;
        }
    } while(ch != 4);
    return 0;
}