changes as per request

Author: VaishnaviMankala19

contrib/ds-algorithms/deque.md

@@ -19,86 +19,134 @@ d = deque(iterable)  # Create deque from iterable (optional)
     - append(x): Adds element x to the right end of the deque.
     - appendleft(x): Adds element x to the left end of the deque.
 
+    ### Program
+    ```py
+    from collections import deque
+
+    # Initialize a deque
+    d = deque([1, 2, 3, 4, 5])
+    print("Initial deque:", d)
+
+    # Append elements
+    d.append(6)
+    print("After append(6):", d)
+
+    # Append left
+    d.appendleft(0)
+    print("After appendleft(0):", d)
+
+    ```
+    ### Output
+    ```py
+    Initial deque: deque([1, 2, 3, 4, 5])
+    After append(6): deque([1, 2, 3, 4, 5, 6])
+    After appendleft(0): deque([0, 1, 2, 3, 4, 5, 6])
+    ```
+
 2. **Removing Elements**:
 
     - pop(): Removes and returns the rightmost element.
     - popleft(): Removes and returns the leftmost element.
 
+    ### Program
+    ```py
+    from collections import deque
+
+    # Initialize a deque
+    d = deque([1, 2, 3, 4, 5])
+    print("Initial deque:", d)
+
+    # Pop from the right end
+    rightmost = d.pop()
+    print("Popped from right end:", rightmost)
+    print("Deque after pop():", d)
+
+    # Pop from the left end
+    leftmost = d.popleft()
+    print("Popped from left end:", leftmost)
+    print("Deque after popleft():", d)
+
+    ```
+    
+    ### Output
+    ```py
+    Initial deque: deque([1, 2, 3, 4, 5])
+    Popped from right end: 5
+    Deque after pop(): deque([1, 2, 3, 4])
+    Popped from left end: 1
+    Deque after popleft(): deque([2, 3, 4])
+    ```
+
 3. **Accessing Elements**:
 
     - deque[index]: Accesses element at index.
 
+    ### Program
+    ```py
+    from collections import deque
+
+    # Initialize a deque
+    d = deque([1, 2, 3, 4, 5])
+    print("Initial deque:", d)
+
+    # Accessing elements
+    print("Element at index 2:", d[2])
+
+    ```
+
+    ### Output
+    ```py
+    Initial deque: deque([1, 2, 3, 4, 5])
+    Element at index 2: 3
+
+    ```
+
 4. **Other Operations**:
 
     - extend(iterable): Extends deque by appending elements from iterable.
     - extendleft(iterable): Extends deque by appending elements from iterable to the left.
     - rotate(n): Rotates deque n steps to the right (negative n rotates left).
 
-## Example
-
-### 1. showing all the operations
-```py
-from collections import deque
+    ### Program
+    ```py
+    from collections import deque
 
-# Initialize a deque
-d = deque([1, 2, 3, 4, 5])
-print("Initial deque:", d)
+    # Initialize a deque
+    d = deque([1, 2, 3, 4, 5])
+    print("Initial deque:", d)
 
-# Append elements
-d.append(6)
-print("After append(6):", d)
+    # Extend deque
+    d.extend([6, 7, 8])
+    print("After extend([6, 7, 8]):", d)
 
-# Append left
-d.appendleft(0)
-print("After appendleft(0):", d)
+    # Extend left
+    d.extendleft([-1, 0])
+    print("After extendleft([-1, 0]):", d)
 
-# Pop from the right end
-rightmost = d.pop()
-print("Popped from right end:", rightmost)
-print("Deque after pop():", d)
+    # Rotate deque
+    d.rotate(2)
+    print("After rotate(2):", d)
 
-# Pop from the left end
-leftmost = d.popleft()
-print("Popped from left end:", leftmost)
-print("Deque after popleft():", d)
+    # Rotate left
+    d.rotate(-3)
+    print("After rotate(-3):", d)
 
-# Accessing elements
-print("Element at index 2:", d[2])
+    ```
 
-# Extend deque
-d.extend([6, 7, 8])
-print("After extend([6, 7, 8]):", d)
+    ### Output
+    ```py
+    Initial deque: deque([1, 2, 3, 4, 5])
+    After extend([6, 7, 8]): deque([1, 2, 3, 4, 5, 6, 7, 8])
+    After extendleft([-1, 0]): deque([0, -1, 1, 2, 3, 4, 5, 6, 7, 8])
+    After rotate(2): deque([7, 8, 0, -1, 1, 2, 3, 4, 5, 6])
+    After rotate(-3): deque([1, 2, 3, 4, 5, 6, 7, 8, 0, -1])
 
-# Extend left
-d.extendleft([-1, 0])
-print("After extendleft([-1, 0]):", d)
+    ```
 
-# Rotate deque
-d.rotate(2)
-print("After rotate(2):", d)
 
-# Rotate left
-d.rotate(-3)
-print("After rotate(-3):", d)
-```
-Output 
-```py
-Initial deque: deque([1, 2, 3, 4, 5])
-After append(6): deque([1, 2, 3, 4, 5, 6])
-After appendleft(0): deque([0, 1, 2, 3, 4, 5, 6])
-Popped from right end: 6
-Deque after pop(): deque([0, 1, 2, 3, 4, 5])
-Popped from left end: 0
-Deque after popleft(): deque([1, 2, 3, 4, 5])
-Element at index 2: 3
-After extend([6, 7, 8]): deque([1, 2, 3, 4, 5, 6, 7, 8])
-After extendleft([-1, 0]): deque([0, -1, 1, 2, 3, 4, 5, 6, 7, 8])
-After rotate(2): deque([7, 8, 0, -1, 1, 2, 3, 4, 5, 6])
-After rotate(-3): deque([1, 2, 3, 4, 5, 6, 7, 8, 0, -1])
-
-```
+## Example
 
-### 2. Finding Maximum in Sliding Window
+### 1. Finding Maximum in Sliding Window
 ```py
 from collections import deque