剑指 Offer 31. 栈的压入、弹出序列

class Solution {
    
    public boolean validateStackSequences(int[] pushed, int[] popped) {
    
        Deque<Integer> q = new LinkedList<>();
        int idx = 0;
        for(int x : pushed){
    
            q.push(x);
            while(!q.isEmpty() && q.peek() == popped[idx]){
                    
                 q.pop();
                 idx++;
            }
        }
        return q.isEmpty();
    }
}