HackerRank Python (Complete 115 Solutions) [33+ Hours]

Explore printing hello world in Python, using strings and variables, and practice a simple print statement with the sample output 'Hello world'; no input is required in this challenge.

Learn to work with nested lists in Python by extracting the names of students who have the second lowest score, including handling ties and sorting names alphabetically.

Learn to compute a student's percentage by averaging marks in Python, handle input for multiple students with a for loop, and format the result to two decimal places with constraints.

Explore how to split a string by a delimiter in Python and then join the pieces with a dash, turning the string into a list of substrings and back.

Practice reading a first name and last name, enforce a maximum length of ten for each, and print the names in the format 'first name last name' using string concatenation.

Learn to mutate a Python string by converting it to a list, changing a character by index, and joining back, with slicing as an alternative.

Build a text wrap function to split a long string into lines of a max width and return a single string with newline breaks.

Explore solving the designer door mat puzzle by generating the m by n pattern with a center welcome, using Python input parsing, string multiplication, and looping to build the design.

master text alignment by implementing left, center, and right options for a string, filling in the blank code, and testing to match the target layout.

Explore how to generate the cartesian product using itertools.product, import the function, and implement a robust Python routine that prints all pairs from two input sequences in a space-separated format.

Learn to use collections.Counter in Python to count items, apply it to a shoe shop scenario, and compute revenue by matching sizes to customer offers.

Convert complex numbers into polar coordinates by computing the distance from the origin and the angle from the positive x-axis, using Python's complex type and printing results to three decimals.

Explore sets by removing duplicates, testing membership, and calculating the average of distinct heights by converting input to a set and printing the result to three decimal places.

Explore how Python's defaultdict from the collections module provides a default value for missing keys, manage key-value pairs efficiently, and apply it to practice problems with dictionaries.

The minion game is described, with two players Stuart and Kevin building substrings from consonants and vowels respectively, scoring each substring occurrence to decide the winner.

Learn to use Python's collections.OrderedDict to preserve first-seen item order while computing net prices for supermarket orders.

Learn how to use the set .add() operation to count distinct country stamps by adding each input to a set and returning the set's length.

Learn to use the set union operation in Python to combine English and French newspaper subscribers and count the number of students with at least one subscription.

Explore Python set difference using dot and dash operators to subtract French subscribers from English newspaper subscribers and compute the total English subscribers.

Generate an n by m identity-like matrix with a one on the main diagonal and zeros elsewhere, adjustable by a key to shift to the upper or lower diagonals.

Learn to compute minimum and maximum across multi-dimensional arrays by applying min along an axis (0 or 1) or none, then take the maximum of those results.

solve the captain's room puzzle by detecting the single captain's room number among room entries. use set to remove duplicates and compute captain's room via (sum(unique)*k - sum(all)) / (k-1).

Explore how Python handles arbitrarily large integers and rapid exponent growth by computing large power expressions with A, B, C, and D, illustrating no size limit unlike C++.

Learn to detect floating point numbers in strings using Python regular expressions, covering start conditions, exactly one dot, at least one decimal digit, and handling errors with try-except.

Validate roman numerals with regular expressions up to 3999, applying subtractive notation for four and nine, and map symbols M, D, C, L, X, V, I across thousands to units.

Debug the word score problem by fixing a bug in is_score_words to correctly count words with an even number of vowels and sum their scores using the provided template.

Identify the three most common lowercase characters in a string by counting occurrences, sorting by frequency in descending order, and breaking ties alphabetically; output the characters with their counts.

Sort athletes by a chosen attribute from the spreadsheet (age, height, weight) and, when attributes tie, preserve the order they appeared to produce a final ranked table.

Master iterables and iterators by solving a probability problem with Python's combinations, counting selections where at least one chosen element contains the letter a.

Explore regex substitution in Python by applying a function or lambda to each match to transform strings, including squaring numbers and replacing patterns, with careful handling of spaces and escapes.

Learn how default arguments in Python control function behavior when arguments are omitted, and how to debug state initialization in a stream-based function to produce correct odd or even sequences.

Learn to validate emails in Python using a filter with a custom validity function. The lecture explains username rules and extension constraints and shows lexical order sorting of valid emails.

Detect html tags, start tags, attributes, and attribute values by parsing code lines and printing each tag with its attributes and values in the required format.

Validate and parse email addresses by enforcing username, domain, and extension formats, ensuring alphabetic starts and a 1-3 letter extension, then print names with valid emails in input order.

Master implementing a complex number class to perform add, subtract, multiply, divide, and modulus, with precise three-decimal output and format rules across languages like C++ and Java.

Learn how any and all evaluate iterables in Python, returning true when any or all elements satisfy a condition, with examples on positive numbers and palindromic integers.