队列&栈
队列:先入先出的数据结构
1、设计循环队列
class MyCircularQueue {
private:
vector<int> data;
int head;
int tail;
int size;
public:
/** Initialize your data structure here. Set the size of the queue to be k. */
MyCircularQueue(int k) {
data.resize(k);
head=-1;
tail=-1;
size=k;
}
/** Insert an element into the circular queue. Return true if the operation is successful. */
bool enQueue(int value) {
if(isFull())
return false;
if(isEmpty())
{
head=0;
}
tail=(tail+1)%size;
data[tail]=value;
return true;
}
/** Delete an element from the circular queue. Return true if the operation is successful. */
bool deQueue() {
if(isEmpty())
{
return false;
}
if(head==tail)
{
head=-1;
tail=-1;
return true;
}
head=(head+1)%size;
return true;
}
/** Get the front item from the queue. */
int Front() {
if(isEmpty())
return -1;
return data[head];
}
/** Get the last item from the queue. */
int Rear() {
if(isEmpty())
return -1;
return data[tail];
}
/** Checks whether the circular queue is empty or not. */
bool isEmpty() {
return head==-1;
}
/** Checks whether the circular queue is full or not. */
bool isFull() {
return (tail+1)%size==head;
}
};
/**
* Your MyCircularQueue object will be instantiated and called as such:
* MyCircularQueue* obj = new MyCircularQueue(k);
* bool param_1 = obj->enQueue(value);
* bool param_2 = obj->deQueue();
* int param_3 = obj->Front();
* int param_4 = obj->Rear();
* bool param_5 = obj->isEmpty();
* bool param_6 = obj->isFull();
*/