max stack

import java.util.LinkedList;class MaxStack { Listlist; Queuequeue;

/** initialize your data structure here. */

public MaxStack() {

list = new ArrayList<>();

queue = new PriorityQueue<>(10000, Collections.reverseOrder());

}

public void push(int x) {

list.add(x);

queue.offer(x);

}

public int pop() {

int temp = list.remove(list.size() - 1);

queue.remove(temp);

return temp;

}

public int top() {

return list.get(list.size() - 1);

}

public int peekMax() {

return queue.peek();

}

public int popMax() {

Integer temp = queue.poll();

for(int i = list.size() - 1; i >= 0; i--){

if(list.get(i).equals(temp)){

list.remove(i);

break;

}

}

return (int)temp;

}

}

/**

* Your MaxStack object will be instantiated and called as such:

* MaxStack obj = new MaxStack();

* obj.push(x);

* int param_2 = obj.pop();

* int param_3 = obj.top();

* int param_4 = obj.peekMax();

* int param_5 = obj.popMax();

*/