Complete the following linked list implementation of STACK in C++ to include two other member functions int peek() and void flush(). Function int peek() returns the top element of the stack without popping this element of the stack. Function void flush() displays the entire stack content, and empties the stack. Do not call empty() and pop() functions in flush(). Function flush() displays an empty line if the stack is empty. class STACK { private: struct node { int item; node* next; node(int x, node* t) { item = x; next = t; } }; typedef node *link; link head; public: STACK(int) { head = 0; } int empty() const { return head == 0; } void push(int x) { head = new node(x, head); } int peek() { /* implement this part */ } int pop() { int v = head->item; link t = head->next; delete head; head = t; return v; } void flush() { /* implement this part */ } }; Write a C++ program that creates a stack of integer numbers (for up to 100 numbers), and then it does the following on users input (your program must check for conditions: e.g. no pop when the stack is empty): P x : pushes integer x onto the stack R : pops off and displays the stack top E : outputs empty if stack is empty; otherwise not empty K : outputs the stack top integer x using function peek F : outputs the entire content of the stack in last-in-first-out order; empties the stack using function flush Example Dialogue (input can be read from a specific file, or can be directed to a file): E empty P 1 P 10 E not empty K 10 P 19 R 19 R 10 E not empty P 5 P 20 F 20 5 1 E empty R nothing to pop off; the stack is empty P 2 E not empty