标签:队列 cal 两个栈 this import 返回 util instant class
用两个栈实现一个队列。队列的声明如下,请实现它的两个函数 appendTail 和 deleteHead ,分别完成在队列尾部插入整数和在队列头部删除整数的功能。(若队列中没有元素,deleteHead?操作返回 -1 )来源:力扣(LeetCode)
链接:https://leetcode-cn.com/problems/yong-liang-ge-zhan-shi-xian-dui-lie-lcof
著作权归领扣网络所有。商业转载请联系官方授权,非商业转载请注明出处。
import java.util.Stack;
class CQueue {
private Stack<Integer> s1;
private Stack<Integer> s2;
public CQueue() {
this.s1 = new Stack<>();
this.s2 = new Stack<>();
}
public void appendTail(int value) {
s1.push(value);
}
public int deleteHead() {
if (s2.isEmpty()) {
while (! s1.isEmpty()) {
s2.push(s1.pop());
}
if (s2.isEmpty()) {
return -1;
}
}
return s2.pop();
}
}
/**
* Your CQueue object will be instantiated and called as such:
* CQueue obj = new CQueue();
* obj.appendTail(value);
* int param_2 = obj.deleteHead();
*/
标签:队列 cal 两个栈 this import 返回 util instant class
原文地址:https://blog.51cto.com/tianyiya/2530932