题解 | #【模板】队列#

#include

#include

using namespace std;

class Queue {

private:

int* data;
int front1, rear;
int count;
int size;

public:

Queue(int capacity);
~Queue();
void push(int e);
bool isEmpty();
bool isFull();
void pop();
void front();

};

Queue::Queue(int capacity) {

data = new int[capacity];
size = capacity;
count = 0;
front1 = rear = 0;

}

Queue::~Queue() {

delete[] data;

}

void Queue::push(int e) {

if (isFull()) {
    return;
}
data[rear] = e;
rear = (rear + 1) % size;
count++;

}

void Queue::pop() {

if (isEmpty()) {
    cout << "error" << endl;
    return;
} 
cout << data[front1] << endl;
front1 = (front1 + 1) % size;
count--;

}

void Queue::front() {

if (isEmpty()) {
    cout << "error" << endl;
    return;
}
cout << data[front1] << endl;

}

bool Queue::isFull() {

return count == size;

}

bool Queue::isEmpty() {

return count == 0;

}

int main() {

int n;
cin>>n;
Queue q(n);
string s;
int t;
for (int i = 0; i < n; i++) {
    cin >> s;
    if (s == "push") {
        cin >> t;
        q.push(t);
    } else if (s == "pop") {
        q.pop();
    } else if (s == "front") {
        q.front();
    }
}

}