PHP
hard
Date
Determining the day of the week for an arbitrary date according to the Gregorian calendar
Write a PHP script that accepts a date in the format 'YYYY-MM-DD' and outputs the day of the week in Russian. The date c…
✅ 0 solved
📅 2026-05-11
C#
medium
Generics
Generalized static array analyzer
Implement a static method `AnalyzeArray` in the generic class `ArrayAnalyzer`, which takes an array of elements of type …
✅ 0 solved
📅 2026-05-11
TypeScript
medium
Algorithms
Sorting objects by multiple fields
Write a program that takes a list of objects with fields name (string) and age (number). Sort the list first by age in a…
✅ 0 solved
📅 2026-05-11
Kotlin
medium
Algorithms
Sorting in descending order with parity consideration
Write a program that sorts an array of integers in descending order, but with a special rule: first should come all odd …
✅ 0 solved
📅 2026-05-11
C++
medium
Vectors
Removing duplicates from a sorted vector with counting
Given a vector of integers sorted in ascending order. It is necessary to remove all duplicates, leaving only unique elem…
✅ 0 solved
📅 2026-05-11
Python
medium
Algorithms
Sorting by frequency and value
Given an array of integers. Sort it in descending order of the frequency of occurrence of elements. If two elements occu…
✅ 0 solved
📅 2026-05-11
Swift
medium
Algorithms
Sorting in descending order with duplicate removal
Given an array of integers, it is necessary to sort it in descending order, removing all duplicate elements. Implement t…
✅ 0 solved
📅 2026-05-11
JavaScript
medium
Algorithms
Sorting by sum of digits and length
Write a program that takes an array of integers and sorts it in ascending order of the sum of the digits of each number.…
✅ 0 solved
📅 2026-05-11
Rust
easy
Math
Sum of squares of numbers from 1 to N
Given a natural number N (1 ≤ N ≤ 1000), calculate the sum of squares of numbers from 1 to N. For example, for N=3 the s…
✅ 0 solved
📅 2026-05-11
PHP
medium
Regex
Extracting IP addresses from text
Write a PHP program that reads lines from standard input and extracts all valid IPv4 addresses from them. An IP address …
✅ 0 solved
📅 2026-05-11
Go
medium
Algorithms
Sorting by number of divisors
Write a program that sorts an array of integers in ascending order of the number of their positive divisors. If two numb…
✅ 0 solved
📅 2026-05-11
Java
medium
Collections
Unique pairs of numbers in collections
You are given two lists of integers. You need to find all unique pairs (a, b), where a belongs to the first list, b belo…
✅ 0 solved
📅 2026-05-11
TypeScript
easy
Math
Sum of squares of even numbers
Write a program that takes an integer N, then N integers. Calculate the sum of squares of only the even numbers from the…
✅ 0 solved
📅 2026-05-11
Kotlin
easy
Math
Sum of digits of a number
Write a program that calculates the sum of digits of a positive integer. The number can be large, up to 10^9. If the num…
✅ 0 solved
📅 2026-05-11
Rust
hard
Enums
Transformation of an expression tree using enum and pattern matching
Given an arithmetic expression represented as a binary tree. Each tree node is either a number (leaf) or an operation (a…
✅ 0 solved
📅 2026-05-11
C#
easy
Algorithms
Sorting by word length
Write a program that reads a string containing several words separated by spaces. The program should sort the words in a…
✅ 0 solved
📅 2026-05-11
Python
easy
Math
Checking if a number is prime
Write a program that checks whether a given natural number is prime. A prime number is a natural number greater than 1 t…
✅ 0 solved
📅 2026-05-11
C++
easy
Algorithms
Sorting an array in ascending order
Given an array of integers. Sort it in ascending order using any sorting algorithm. Output the sorted array.…
✅ 0 solved
📅 2026-05-11
Swift
easy
Math
Sum of even numbers from A to B
Given two integers A and B (A ≤ B). Find the sum of all even numbers in the range from A to B inclusive. Implement a sol…
✅ 0 solved
📅 2026-05-11
Go
easy
Math
Sum of even Fibonacci numbers
Write a program that finds the sum of all even numbers in the Fibonacci sequence that do not exceed a given number N. Th…
✅ 0 solved
📅 2026-05-11
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