Data-Structures-Algorithms/Structures/Stack.java at master · hound77/Data-Structures-Algorithms · GitHub

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import java.lang.IndexOutOfBoundsException;

import java.util.Arrays;

public class Stack<E> {

private int max;

private int top;

private Object[] list;

public Stack() {

max = 512;

top = 0;

list = new Object[max];

}

public Stack(int size) {

max = size;

top = 0;

list = new Object[max];

}

@SuppressWarnings("unchecked")

public boolean isEmpty() {

for(E t : (E[]) list) {

if(t != null) {

return false;

}

return true;

}

@SuppressWarnings("unchecked")

public E peek() {

return (E) list[top];

}

@SuppressWarnings("unchecked")

public int size() {

if(top == 0) {

return 0;

}

int count = 0;

for(E t : (E[]) list) {

if(t != null) {

count++;

}

return count;

}

@SuppressWarnings("unchecked")

public E pop() {

if(isEmpty()) {

throw new IndexOutOfBoundsException("This stack is empty; nothing to pop.");

}

E data = (E) list[top];

top = (top == 0 ? 0 : top - 1);

return data;

}

public void push(E data) {

if(top == max - 1) {

list = Arrays.copyOf(list, list.length * 2);

}

top++;

list[top] = data;

}

Data-Structures-Algorithms/Structures/Stack.java at master · hound77/Data-Structures-Algorithms · GitHub

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