Algorithms Hands-on

Fib.py

def fib(n, depth=0):
    indent = "  " * depth  # Indentation for better visualization
    print(f"{indent}fib({n}) called")

    if n == 0:
        print(f"{indent}Returning 0")
        return 0
    if n == 1:
        print(f"{indent}Returning 1")
        return 1

    result = fib(n - 1, depth + 1) + fib(n - 2, depth + 1)
    print(f"{indent}Returning {result} from fib({n})")
    return result

merge.py

def merge_two_sorted_arrays(arr1, arr2):
    """Merges two sorted arrays into a single sorted array."""
    i, j = 0, 0
    merged = []
    
    while i < len(arr1) and j < len(arr2):
        if arr1[i] < arr2[j]:
            merged.append(arr1[i])
            i += 1
        else:
            merged.append(arr2[j])
            j += 1

    # Add remaining elements, if any
    while i < len(arr1):
        merged.append(arr1[i])
        i += 1
    while j < len(arr2):
        merged.append(arr2[j])
        j += 1
    
    return merged

def merge_k_sorted_arrays(arrays):
    """Merges K sorted arrays into a single sorted array."""
    if not arrays:
        return []
    
    merged_array = arrays[0]
    
    for i in range(1, len(arrays)):
        merged_array = merge_two_sorted_arrays(merged_array, arrays[i])
    
    return merged_array

# Example usage:
arrays = [
    [1, 3, 5, 7],
    [2, 4, 6, 8],
    [0, 9, 10, 11]
]

result = merge_k_sorted_arrays(arrays)
print(result)  # Output: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]

remove.py

def remove_duplicates(array):
    # Check if the array is empty
    if not array:
        return []

    # Initialize the result array with the first element
    result = [array[0]]

    # Traverse the array from the second element onwards
    for i in range(1, len(array)):
        # If the current element is different from the last added element
        if array[i] != array[i - 1]:
            result.append(array[i])

    return result

# Example usage
array1 = [2, 2, 2, 2, 2]
array2 = [1, 2, 2, 3, 4, 4, 4, 5, 5]

print(remove_duplicates(array1))  # Output: [2]
print(remove_duplicates(array2))  # Output: [1, 2, 3, 4, 5]