1- given the definition of the class 'StackArray' to implement a stack using arrays. Complete the implementation of methods- push, pop, and peek. public class StackArray { int[] s=new int[5];...

1- given the definition of the class 'StackArray' to implement a stack using arrays. Complete the implementation of methods- push, pop, and peek.

public class StackArray {

int[] s=new int[5];

int top=-1;

public boolean isempty( ){

return top == -1;

}

public boolean isfull( ){

return top == s.length-1;

}

 public void push(int e) {

}

 public int pop( ) {

}

 public int peek( ) {

}

}

2- Write Java code to:

a: Create a Deque object containing all integers from 1 to 20.

b: Display the front and rear elements

c: Display all elements in reverse order.