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 )
示例 1：
输入：
["CQueue","appendTail","deleteHead","deleteHead"]
[[],[3],[],[]]
输出：[null,null,3,-1]
["CQueue","appendTail","deleteHead","deleteHead"]
[[],[3],[],[]]
输出：[null,null,3,-1]
我的题解：
class CQueue {
private int[] stack;
private int top ;
public CQueue() {
stack=new int[1001];
top=-1;
}
public void appendTail(int value) {
stack[++top]=value;
}
public int deleteHead() {
if (top==-1) {
return -1;
}
CQueue testQueue=new CQueue();
for (int i = top; i >=0 ; i--) {
testQueue.stack[++testQueue.top]=stack[i];
}
int deleteHead=testQueue.stack[top];
for (int i = --top,j=0; i >= 0; i--) {
stack[j++]=testQueue.stack[i];
}
return deleteHead;
}
}
/**
* Your CQueue object will be instantiated and called as such:
* CQueue obj = new CQueue();
* obj.appendTail(value);
* int param_2 = obj.deleteHead();
*/