From e59257ffbbc9dd084f5180547a4d9a527729cc9b Mon Sep 17 00:00:00 2001
From: mohit0312 <44519237+mohit0312@users.noreply.github.com>
Date: Sat, 23 Oct 2021 11:30:00 +0530
Subject: [PATCH] Create reverseStringUsingStack

Reverse a string using stack
---
 reverseStringUsingStack | 81 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 reverseStringUsingStack

diff --git a/reverseStringUsingStack b/reverseStringUsingStack
new file mode 100644
index 0000000..0c76dcc
--- /dev/null
+++ b/reverseStringUsingStack
@@ -0,0 +1,81 @@
+// C++ program to reverse a string using stack
+#include <bits/stdc++.h>
+using namespace std;
+
+// A structure to represent a stack
+class Stack
+{
+	public:
+	int top;
+	unsigned capacity;
+	char* array;
+};
+
+// function to create a stack of given
+// capacity. It initializes size of stack as 0
+Stack* createStack(unsigned capacity)
+{
+	Stack* stack = new Stack();
+	stack->capacity = capacity;
+	stack->top = -1;
+	stack->array = new char[(stack->capacity * sizeof(char))];
+	return stack;
+}
+
+// Stack is full when top is equal to the last index
+int isFull(Stack* stack)
+{ return stack->top == stack->capacity - 1; }
+
+// Stack is empty when top is equal to -1
+int isEmpty(Stack* stack)
+{ return stack->top == -1; }
+
+// Function to add an item to stack.
+// It increases top by 1
+void push(Stack* stack, char item)
+{
+	if (isFull(stack))
+		return;
+	stack->array[++stack->top] = item;
+}
+
+// Function to remove an item from stack.
+// It decreases top by 1
+char pop(Stack* stack)
+{
+	if (isEmpty(stack))
+		return -1;
+	return stack->array[stack->top--];
+}
+
+// A stack based function to reverse a string
+void reverse(char str[])
+{
+	// Create a stack of capacity
+	//equal to length of string
+	int n = strlen(str);
+	Stack* stack = createStack(n);
+
+	// Push all characters of string to stack
+	int i;
+	for (i = 0; i < n; i++)
+		push(stack, str[i]);
+
+	// Pop all characters of string and
+	// put them back to str
+	for (i = 0; i < n; i++)
+		str[i] = pop(stack);
+}
+
+// Driver code
+int main()
+{
+	char str[] = "GeeksQuiz";
+
+	reverse(str);
+	cout << "Reversed string is " << str;
+
+	return 0;
+}
+
+// This code is contributed by rathbhupendra