leetcode/stackqueues/lb-02-implement-queue.cpp at main · okmd/leetcode · GitHub

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#include <iostream>

#include <string>

#include <vector>

using namespace std;

class Queue {

public:

int size;

int capacity;

int *arr;

int front, rear;

Queue(int cap = 10) {

capacity = cap;

size = 0;

arr = new int[capacity];

front = 0;

rear = capacity - 1;

}

bool empty() {

return size == 0;

}

bool full() {

return size == capacity;

}

bool enqueue(int val) {

if (!full()) {

rear = (rear + 1) % capacity;

arr[rear] = val;

size++;

return true;

}

cout << "Overflow\n";

return false;

}

int dequeue() {

if (!empty()) {

int item = arr[front];

front = (front + 1) % capacity;

size--;

return item;

}

cout << "Underflow\n";

return INT_MIN;

}

int get_rear() {

if (!empty())

return arr[rear];

return INT_MIN;

}

};

int main() {

Queue q = Queue(4);

q.enqueue(1);

cout << q.dequeue() << endl;

cout << q.dequeue() << endl;

q.enqueue(1);

q.enqueue(2);

q.enqueue(3);

q.enqueue(4);

q.enqueue(5);

cout << q.get_rear() << endl;

return 0;

}