剑指 Offer 09. 用两个栈实现队列
class CQueue {
Deque<Integer> stack1;
Deque<Integer> stack2;
public CQueue() {
stack1 = new LinkedList<Integer>();
stack2 = new LinkedList<Integer>();
}
public void appendTail(int value) {
stack1.push(value);
}
public int deleteHead() {
// 如果第二个栈为空
if (stack2.isEmpty()) {
while (!stack1.isEmpty()) {
stack2.push(stack1.pop());
}
}
if (stack2.isEmpty()) {
return -1;
} else {
int deleteItem = stack2.pop();
return deleteItem;
}
}
// 作者：LeetCode-Solution
// 链接：https://leetcode-cn.com/problems/yong-liang-ge-zhan-shi-xian-dui-lie-lcof/solution/mian-shi-ti-09-yong-liang-ge-zhan-shi-xian-dui-l-3/
}
