LC_2349_DesignaNumberContainerSystem

class NumberContainers {
    Map<Integer, Integer> map;
    Map<Integer, PriorityQueue<Integer>> revMap;


    public NumberContainers() {
        map = new HashMap<>();
        revMap = new HashMap<>();
    }
    
    public void change(int index, int number) {
        map.put(index, number);
        if(!revMap.containsKey(number)){
            revMap.put(number, new PriorityQueue<>());
        }
        revMap.get(number).offer(index);
    }
    
    public int find(int number) {
        if(!revMap.containsKey(number)){
            return -1;
        }
        PriorityQueue<Integer> pq = revMap.get(number);
        while(!pq.isEmpty()){
            int idx = pq.peek();
            if(map.get(idx) == number){
                break;
            } else {
                pq.poll();
            }
        }
        if(pq.isEmpty()){
            revMap.remove(number);
            return -1;
        }
        return revMap.get(number).peek();
    }
}

/**
 * Your NumberContainers object will be instantiated and called as such:
 * NumberContainers obj = new NumberContainers();
 * obj.change(index,number);
 * int param_2 = obj.find(number);
 */