First Unique Number

class FirstUnique {
    private Queue<Integer> queue = new LinkedList<>();
    private Map<Integer, Integer> map = new HashMap<>();
    public FirstUnique(int[] nums) {
        
        for(int i : nums){
            if(map.containsKey(i)){
                map.replace(i, map.get(i)+1);
            }
            else{
                map.put(i, 1);
            }
            queue.add(i);
            
        }
        
    }
    
    public int showFirstUnique() {
        
        while(!queue.isEmpty() && map.get(queue.peek())>1){
            queue.poll();
        }
        if(queue.isEmpty()){
            return -1;
        }
        return queue.peek();
    }
    
    public void add(int value) {
        if(map.containsKey(value)){
            map.replace(value, map.get(value)+1);
        }
        else{
            map.put(value,1);
            queue.add(value);
        }
    }
}

/**
 * Your FirstUnique object will be instantiated and called as such:
 * FirstUnique obj = new FirstUnique(nums);
 * int param_1 = obj.showFirstUnique();
 * obj.add(value);
 */