queue in c++
#include <queue> queue<int> q; q.push(10); q.push(20); q.front(); // 10 q.back(); // 20 while (!q.empty()) q.pop();
Queue operations C++
#include<iostream>
using namespace std;
class Queue {
private:
int front;
int rear;
int arr[5];
public:
Queue() {
front = -1;
rear = -1;
for (int i = 0; i < 5; i++) {
arr[i] = 0;
}
}
bool isEmpty() {
if (front == -1 && rear == -1)
return true;
else
return false;
}
bool isFull() {
if (rear == 4)
return true;
else
return false;
}
void enqueue(int val) {
if (isFull()) {
cout << "Queue full" << endl;
return;
} else if (isEmpty()) {
rear = 0;
front = 0;
arr[rear] = val;
} else {
rear++;
arr[rear] = val;
}
}
int dequeue() {
int x = 0;
if (isEmpty()) {
cout << "Queue is Empty" << endl;
return x;
} else if (rear == front) {
x = arr[rear];
rear = -1;
front = -1;
return x;
} else {
cout << "front value: " << front << endl;
x = arr[front];
arr[front] = 0;
front++;
return x;
}
}
int count() {
return (rear - front + 1);
}
void display() {
cout << "All values in the Queue are - " << endl;
for (int i = 0; i < 5; i++) {
cout << arr[i] << " ";
}
}
};
int main() {
Queue q1;
int value, option;
do {
cout << "\n\nWhat operation do you want to perform? Select Option number. Enter 0 to exit." << endl;
cout << "1. Enqueue()" << endl;
cout << "2. Dequeue()" << endl;
cout << "3. isEmpty()" << endl;
cout << "4. isFull()" << endl;
cout << "5. count()" << endl;
cout << "6. display()" << endl;
cout << "7. Clear Screen" << endl << endl;
cin >> option;
switch (option) {
case 0:
break;
case 1:
cout << "Enqueue Operation \nEnter an item to Enqueue in the Queue" << endl;
cin >> value;
q1.enqueue(value);
break;
case 2:
cout << "Dequeue Operation \nDequeued Value : " << q1.dequeue() << endl;
break;
case 3:
if (q1.isEmpty())
cout << "Queue is Empty" << endl;
else
cout << "Queue is not Empty" << endl;
break;
case 4:
if (q1.isFull())
cout << "Queue is Full" << endl;
else
cout << "Queue is not Full" << endl;
break;
case 5:
cout << "Count Operation \nCount of items in Queue : " << q1.count() << endl;
break;
case 6:
cout << "Display Function Called - " << endl;
q1.display();
break;
case 7:
system("cls");
break;
default:
cout << "Enter Proper Option number " << endl;
}
} while (option != 0);
return 0;
}Source: simplesnippets.tech
queue cpp
#include <queue> queue<int> gquiz; gquiz.push(10); gquiz.push(20); gquiz.push(30);