implement stack and so its push, pop, and peek operation..cpp

#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\n";
}

void peek() {
	if(top == -1){
		cout<<"Stack is empty\n";
	}
	else
	 cout<<"The top element is: "<< stack[top] <<endl;
}

int main() {
   int ch, val;
   cout<<"1) Push in stack"<<endl;
   cout<<"2) Pop from stack"<<endl;
   cout<<"3) Display stack"<<endl;
   cout<<"4) Display Top element of the stack"<<endl;
   cout<<"5) Exit"<<endl;
   do {
      cout<<"\nEnter choice: ";
      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:
			peek();
			break;
		
         case 5: 
            cout<<"Exit"<<endl;
            break;
         
         default: 
            cout<<"Invalid Choice"<<endl;
         
      }
   }
   while(ch!=5);
   return 0;
}