java-dsa/a30circularQueue.java at main · deekshant-tyagi/java-dsa · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
public class a30circularQueue {
    int rear, front;
    int size;
    int[] circularQueue;
    int capacity;

    public a30circularQueue(int capacity) {
        this.capacity = capacity;
        this.circularQueue = new int[capacity];
        front = rear = -1;
        size = 0;
    }

    public boolean isEmpty() {
        if (front == -1) {
            return true;
        }
        return false;
    }

    public boolean isFull() {
        if (size == capacity) {
            return true;
        }
        // if ((front == 0 && rear == capacity - 1) || (front != 0 && rear == (front - 1) % capacity)) {
        //     return true;
        // }
        return false;
    }

    public int peek() {
        if (isEmpty()) {
            System.out.println("Queue is Empty");
            return -1;
        }
        return circularQueue[front];

    }

    public void enqueue(int val) {
        if (isFull()) {
            System.out.println("Queue is Full");
            return;
        }
        if (isEmpty()) {
            front = rear = 0;
        } else if (rear == capacity - 1 && front != 0) {
            rear = 0;
        } else {
            rear++;
        }
        circularQueue[rear] = val;
        size++;
    }

    public int dequeue(){
        if(isEmpty()){
            System.out.println("Queue is Empty");
            return -1;
        }
        int val = circularQueue[front];
        if (front == rear) {
            front = rear  = -1;
        }else if (front == capacity-1) {
            front = 0;
        }else{
            front++;
        }
        size--;
        return val;
    }

    public void printQueue(){
        if(isEmpty()){
            System.out.println("Queue is Empty");
            return;
        }
        if (front <= rear) {//normal case
            for (int i = front; i <= rear; i++) {
                System.out.print(circularQueue[i] + ",");
            }
        } else {
            for (int i = front; i < capacity; i++) {
                System.out.print(circularQueue[i] + ",");
            }
            for (int i = 0; i <= rear; i++) {
                System.out.print(circularQueue[i] + ",");
            }
        }
        System.out.println();
    }
    public int size(){
        return size;
    }


    public static void main(String[] args) {
        a30circularQueue myCircularQueue = new a30circularQueue(5);
        System.out.println("Capacity is: " + 5);
        System.out.println("Print:");
        myCircularQueue.printQueue();
        System.out.println("Insert element :" + 7);
        myCircularQueue.enqueue(7);
        System.out.println("Peak element: " + myCircularQueue.peek());
        System.out.println("Insert element :" + 8);
        myCircularQueue.enqueue(8);
        System.out.println("Peak element: " + myCircularQueue.peek());
        System.out.println("Insert element :" + 9);
        myCircularQueue.enqueue(9);
        System.out.println("Peak element: " + myCircularQueue.peek());
        System.out.println("Insert element :" + 11);
        myCircularQueue.enqueue(11);
        System.out.println("Insert element :" + 19);
        myCircularQueue.enqueue(19);
        System.out.println("Insert element :" + 9);
        myCircularQueue.enqueue(9);
        System.out.println("is CircularQueue full: " + myCircularQueue.isFull());
        System.out.println("Print:");
        myCircularQueue.printQueue();
        System.out.println("delete element");
        myCircularQueue.dequeue();
        System.out.println("is CircularQueue full: " + myCircularQueue.isFull());
        System.out.println("Print:");
        myCircularQueue.printQueue();
        System.out.println("Insert element :" + 19);
        myCircularQueue.enqueue(19);
        System.out.println("Print:");
        myCircularQueue.printQueue();
        System.out.println("Peak element: " + myCircularQueue.peek());
        System.out.println("delete element");
        myCircularQueue.dequeue();
        System.out.println("Peak element: " + myCircularQueue.peek());

        System.out.println("is CircularQueue empty: " + myCircularQueue.isEmpty());

        System.out.println("Print:");
        myCircularQueue.printQueue();
        System.out.println("delete element");
        myCircularQueue.dequeue();
        System.out.println("delete element");
        myCircularQueue.dequeue();
        System.out.println("delete element");
        myCircularQueue.dequeue();
        System.out.println("delete element");
        myCircularQueue.dequeue();
        System.out.println("is CircularQueue empty: " + myCircularQueue.isEmpty());
        System.out.println("Print:");
        myCircularQueue.printQueue();
        System.out.println("delete element");
        myCircularQueue.dequeue();
    }
}