StackUsingQueue

class MyStack {
public:
    //INITIALISE THE DATA STRUCTRURE HERE
    queue<int> q;//QUEUE IMPLEMETED
    MyStack() {
        
    }
    //PUSH ELEMENT ONTO THE STACK
    void push(int x) {
        if(q.empty()) q.push(x);//IF EMPTY THEN DIRECT PUSH
        else{
            int s=q.size();//SIZE OF QUEUE
            q.push(x);//PUSHING OF ELEEMNT
            while(s--){//WHILE S--
                int top=q.front();//TOP ELEEMTN QUEUE KA
                q.pop();//REMOVE THAT ELEMENT AS FIRST IN FIRST OUT FOLLOWED
                q.push(top);//PUSH IN QUEUE AS FOR CHANGING INTO LAST IN FIRST OUT TYPE STACK
            }//LAST IN FIRST OUT KRWA RHE H OKKK PICHE SE NIKAL WA RHE H AND WAPIS USKO ADD KR RHE H
        }
        
    }
    //REMOVES THE ELEMENT ON THE TOP OF THE STACK AND RETURNS THE ELEMT
    int pop() {
        int top=q.front();//TOPMOST ELEMTN IS THE FRONT ELEMET OF QUEUE
        q.pop();//POP
        return top;//RETURN THE TOPMOST ELEMENT
        
    }
    //GETS THE TOP ELEMENT
    int top() {
        return q.front();//TOPMOST ELEMETN DIREFT
        
    }
    //CHECKS WHETER THE STACK IS EMPTY OR NOT
    bool empty() {
        if(q.empty()) return true;
        else return false; 
        
    }
};