Stack, Queue using arrays div-bargali#223

Stack, Queue using arrays

Author: div-bargali

C++/Data-Structures/Queue/Queue_using_Array.cpp

@@ -0,0 +1,108 @@
+#include<bits/stdc++.h>
+using namespace std;
+template <typename T>
+
+class QueueUsingArray {
+T* data;
+int firstIndex;
+int nextIndex;
+int size;
+int capacity;
+public:
+QueueUsingArray() {
+data = new T[5];
+firstIndex = -1;
+nextIndex = 0;
+size = 0;
+capacity = 5;
+}
+int getsize() {
+return size;
+}
+bool isEmpty() {
+return size == 0;
+}
+void enqueue(T element) {
+if (size == capacity)
+{
+int j = 0;
+T* newData = new T[capacity * 2];
+for (int i = firstIndex; i < capacity; i++) {
+newData[j] = data[i];
+j++;
+}
+for (int i = 0; i < firstIndex; i++) {
+newData[j] = data[i];
+j++;
+}
+delete [] data;
+data = newData;
+firstIndex = 0;
+nextIndex = capacity;
+capacity *= 2;
+}
+data[nextIndex] = element;
+nextIndex = (nextIndex + 1) % capacity;
+if (firstIndex == -1) {
+firstIndex = 0;
+}
+size++;
+}
+T front() {
+if (isEmpty()) {
+cout << "Queue is empty!" << endl;
+return 0;
+}
+return data[firstIndex];
+}
+
+T dequeue() {
+if (isEmpty()) {
+cout << "Queue is empty!" << endl;
+return 0;
+}
+T ans = data[firstIndex];
+firstIndex = (firstIndex + 1) % capacity;
+size--;
+if (size == 0) {
+firstIndex = -1;
+nextIndex = 0;
+}
+return ans;
+}
+
+};
+
+
+
+int main() {
+#ifndef ONLINE_JUDGE
+freopen("input.txt", "r", stdin);
+freopen("output.txt", "w", stdout);
+#endif
+QueueUsingArray<int> q;
+q.enqueue(10);
+q.enqueue(20);
+q.enqueue(30);
+q.enqueue(40);
+q.enqueue(50);
+q.enqueue(60);
+q.enqueue(70);
+q.enqueue(80);
+q.enqueue(90);
+cout << q.front() << endl;
+cout << q.dequeue() << endl;
+cout << q.dequeue() << endl;
+cout << q.getsize() << endl;
+cout << q.dequeue() << endl;
+cout << q.dequeue() << endl;
+cout << q.dequeue() << endl;
+cout << q.dequeue() << endl;
+cout << q.dequeue() << endl;
+cout << q.dequeue() << endl;
+cout << q.front() << endl;
+cout << q.isEmpty() << endl;
+
+
+return 0;
+}

C++/Data-Structures/Stack/stack_using_Array.cpp

@@ -0,0 +1,70 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+template<typename T>
+class StackUsingArray {
+T *data;
+int nextIndex;
+int capacity;
+public:
+StackUsingArray() {
+data = new T[capacity];
+capacity = 4;
+nextIndex = 0;
+}
+int size() {
+return nextIndex;
+}
+bool isEmpty() {
+return nextIndex == 0;
+}
+void push(T n) {
+if (nextIndex == capacity) {
+T *newData = new T[2 * capacity];
+for (int i = 0; i < capacity; i++) {
+newData[i] = data[i];
+}
+capacity = capacity * 2;
+delete[] data;
+data = newData;
+
+}
+data[nextIndex] = n;
+nextIndex++;
+}
+T pop() {
+if (isEmpty() == true) {
+cout << "Stack is empty" << endl;
+return 0;
+}
+nextIndex--;
+return data[nextIndex];
+}
+T top() {
+return data[nextIndex - 1];
+}
+
+};
+int main() {
+#ifndef ONLINE_JUDGE
+freopen("input.txt", "r", stdin);
+freopen("output.txt", "w", stdout);
+#endif
+
+StackUsingArray<int> s;
+s.push(101);
+s.push(102);
+s.push(103);
+s.push(104);
+s.push(105);
+
+
+cout << s.size() << endl;
+cout << s.top() << endl;
+cout << s.pop() << endl;
+cout << s.pop() << endl;
+cout << s.pop() << endl;
+cout << s.pop() << endl;
+cout << s.pop() << endl;
+return 0;
+}