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The inverse count of an array indicates how far or how close the array is from being sorted. If the array is already sorted, then the inverse count is zero, but if the array is sorted in reverse order, then the inverse count is maximum. Here we have given an integer array of size n and need to find the inversions in the array. If two array elements arr[i] and arr[j] form an inversion if arr[i]>arr[j] and i
A linked list is a linear data structure in which we store a sequence of elements, where each element is called a node that contains data and a pointer (or link) to the next element in the sequence. In this C++ article, we will implement a Binary search tree using a linked list. Binary Search Tree A binary search tree is a hierarchical data structure that is constructed by nodes. Each node contains a value and its reference to the left and right child nodes. So the value in the left child node is less than the parent node, and ... Read More
Listing files and directories using Python is a common task in many applications, from file management tools to automated scripts. However, when we are working on the Windows Operating System, the hidden files and folders are marked using specific file attributes, which can clutter the output if not handled properly. Unlike Unix-based systems, where hidden files typically start with a dot such as .hidden) whereas Windows uses metadata to mark files as hidden. In this article, we'll explore several methods to list only non-hidden files and directories. Basic Filtering by Name Prefix This is the basic Filtering method, which checks ... Read More
Python dictionaries are very difficult to handle data. They use a special system called hashing, which allows quick access to information. This specifies the cost of different operations: Time Complexities of Dictionary Operations Python dictionaries are usually fast because they use hashing to find and store data. The time complexity of dictionary operations in Python depends on the size of the dictionary and the operations performed. Here are some of the common dictionary operations - ... Read More
In Python, function names follow specific rules. A valid function name can only contain certain characters, and it must follow the naming conventions defined in the Python language syntax. Using the correct characters ensures that your code runs without syntax errors and stays readable. Allowed Characters in Function Names Python function names can consist of the following characters - Letters (A–Z, a–z) Digits (0–9) — but not at the beginning Underscores (_) — often used to separate words Function names must follow these rules - Must start with a letter or underscore Cannot start with a digit ... Read More
You can handle errors in Python using the try and except blocks. Sometimes, we also want to store the actual exception in a variable to print it or inspect it. This is done using the as keyword in modern Python. But if you have seen older code, you might find except Exception e or even except Exception, e being used. In this article, we will explore the difference between these syntaxes, understand why older ones no longer work in Python 3, and learn the best practices for clean exception handling. Understanding Basic Exception Handling Python provides try-except blocks to catch ... Read More
When writing a C extension for Python, you might need to raise an exception if something goes wrong in your C code. Python provides a special C API that helps you to raise errors in a way that works just like regular Python exceptions.This is helpful because even if your code is written in C for better performance, users can still handle errors using Python's normal try...except blocks. It makes your extension feel just like any other Python module.Using Python C API to Raise ExceptionsIn C extensions for Python, you can raise exceptions using the Python C API functions like ... Read More
In Python, a KeyError exception occurs when a dictionary key that does not exist is accessed. This can be avoided by using proper error handling with the try and except blocks, which can catch the error and allow the program to continue running. Understanding KeyError in Python A KeyError is raised when you try to access a key that doesn't exist in a dictionary. It is one of the built-in exceptions that can be handled by Python's try and except blocks. Example: Accessing a non-existent key In this example, we are attempting to access a key that does not exist ... Read More
In Python, you need to use the built-in json module to work with JSON data. When you want to return data from a function in JSON format, you can use the json.dumps() function to convert a Python dictionary (or similar object) into a JSON string. This is helpful when making APIs, sending data in web responses, or saving organized data in files. Using json.dumps() Function The json.dumps function is used to convert a Python object (like a dictionary or list) into a JSON-formatted string. Syntax Following is its basic syntax - json.dumps(python_object) Where python_object is usually a dictionary or list ... Read More
Camel case and snake case are ways of writing words together when we are programming. In camel case, we write words together without spaces and we start each new word with a capital letter except for the first word. For example, if we want to write a variable name for someone's date of birth, we can write it like this: dateOfBirth. In snake case, we write words together with an underscore symbol between them, and all the letters are lowercase. For example, if we want to write a variable name for someone's home address, we can write it like this: ... Read More