# Questions tagged [programming-challenge]

Programming challenges are off-site challenges meant to offer programmers educational experiences while testing their abilities.

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### Sort Array By Parity

The task is taken from leetcode Given an array A of non-negative integers, return an array consisting of all the even elements of A, followed by all the odd elements of A. You may return any ...
39 views

### TLE error: Remove element from LinkedList [closed]

I am working on an easy LinkedList basic operation problem on Remove Linked List Elements - LeetCode Remove Linked List Elements Remove all elements from a linked list of integers that ...
38 views

### Prompting the user to input a data value into an element in a linked list

I'm working through a practice problem that is having me build and modify a linked list over a series of steps. I am particularly interested in knowing if there's a more elegant way of prompting the ...
53 views

### N-Repeated Element in Size 2N Array

The task is taken from leetcode In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times. Return the element repeated N times. ...
31 views

### Items also occurs in a set

The task You're given strings J representing the types of stones that are jewels, and S representing the stones you have. Each character in S is a type of stone you have. You want to know how ...
223 views

### New Year Chaos JavaScript, needs to be sped up

Similar to this question but this is for Python Original problem with description on hacker rank I am currently trying to iterate through a large number of arrays and count how many times numbers ...
471 views

### Determine whether an integer is a palindrome

The task Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward. Example 1: Input: 121 Output: true Example 2: ...
39 views

### Segmented Sieve Spoj

I tried(trying...) to solve the SPOJ prime number problem PRIME1 so i learned and implemented Segmented Sieve correctly but this program works in time for 10^8 but getting Time limit exceeded (TLE) ...
82 views

### LeetCode gas station implementation

There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i ...
72 views

### Determine whether there exists a one-to-one character mapping from one string to another

The task Determine whether there exists a one-to-one character mapping from one string s1 to another s2. For example, given s1 = abc and s2 = bcd, return true since we can map a to b, b to ...
59 views

### Project Euler #5 in C++

I'm currently doing the Project Euler challenges to learn C++. The fifth problem is the following. 2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any ...
80 views

### Find non-duplicated integer in a list where every integer occurs three times except for one integer

The task Given an array of integers where every integer occurs three times except for one integer, which only occurs once, find and return the non-duplicated integer. For example, given [6,...
85 views

### Division without using division, multiplication, or modulus operators

The task Implement division of two positive integers without using the division, multiplication, or modulus operators. Return the quotient as an integer, ignoring the remainder. My solution <...
30 views

### Time limit exceeded in K-th symbol in Grammar (LeetCode)

I am taking efforts to solve problem K-th Symbol in Grammar - LeetCode K-th Symbol in Grammar On the first row, we write a 0. Now in every subsequent ...
4k views

### Project Euler #1 in C++

I'm learning C++ and currently doing Project Euler challenges. The first challenge is the following. If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. ...
194 views

### Finding the upper and lower bound using binary search

I am trying to solve this InterviewBit question https://www.interviewbit.com/problems/search-for-a-range/. My code for this seems to be working properly and it does give me the correct answers on my ...
318 views

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### Sum of two numbers in array

The task You are given two non-empty arrays representing two non-negative integers. The digits are stored in reverse order and each of their items contain a single digit. Add the two numbers ...
82 views

### Find busiest period in building

The task You are given a list of data entries that represent entries and exits of groups of people into a building. An entry looks like this: {"timestamp": 1526579928, count: 3, "type": "...
76 views

### Making Anagram Problem Implementation

Problem Statement Alice is taking a cryptography class and finding anagrams to be very useful. We consider two strings to be anagrams of each other if the first string's letters can be rearranged ...
63 views

### MinMax Problem Implementation

Problem Statement: You will be given a list of integers, arr, and a single integer k. You must create an array of length k from elements of arr such that its unfairness is minimized. Call ...
47 views

### Find indices of two numbers such that they add up to a target

The task ...is taken from leetcode Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have ...
69 views

### Given a list of coordinates, find the rectangle with minimal area

A problem on leetcode asks the coder to write an algorithm to take a bunch of coordinates in the xy-plane and return the minimum area of a rectangle made from four of these coordinates (or return <...
49 views

### Code Chef's Cleaning Tables: find the minimum number of tables to clean

Description: Haku has been newly hired by Chef to clean tables at his restaurant. So whenever a customer wants a table, Haku must clean it. But Haku happens to be a lazy boy. So in the ...
77 views

### Find all pairs of unique indices in a list such that the concatenation of the two words is a palindrome

The task Given a list of words, find all pairs of unique indices such that the concatenation of the two words is a palindrome. For example, given the list ...
112 views

### Rotate a N by N matrix by 90 degrees clockwise

The task: Given an N by N matrix, rotate it by 90 degrees clockwise. For example, given the following matrix: [[1, 2, 3], [4, 5, 6], [7, 8, 9]] you should return: [[7, 4, 1], [8, ...
102 views

### Given a list and a number k return whether any two numbers from the list add up to k

The task: Given a list of numbers and a number k, return whether any two numbers from the list add up to k. For example, given [10, 15, 3, 7] and k of 17, return true since 10 + 7 is 17. ...
61 views

### Check whether string of brackets are well-formed

The task I asked similar questions here and here. Given a string of round, curly, and square open and closing brackets, return whether the brackets are balanced (well-formed). For example, ...
71 views

### Implement integer exponentiation faster than repeated multiplication

The task: Implement integer exponentiation. That is, implement the pow(x, y) function, where x and y are integers and returns x^y. Do this faster than the naive method of repeated ...
62 views

### Polymorphic DBConnector class exercise

GitHub GitHub if it's easier I'm in the process of doing a training course in C#. I've just gone over covering Polymorphic OOP / composition over inheritance etc... The latest exercise I completed ...
1k views

### One-dimensional Japanese puzzle

I have been practicing competitive coding for a while now and am using codeforces.com. I recently encountered a problem called "One Dimensional Japanese Crossword" on that site. The problem is as ...
130 views

### Google Kick Start Practice Round 2019 - Mural

My code exceeds the time limit on the second test set. A suggestion/hint of a better algorithm would be appreciated. Problem Thanh wants to paint a wonderful mural on a wall that is N ...
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### Stopwatch exercise from training course

Github Github for easy testing I'm currently undertaking a training course to try & further develop my skills in C#. The latest exercise was to create a basic stopwatch class that meets the ...
101 views

### Check whether string of braces, brackets, and parentheses is balanced

The Task is taken from codewars: Write a function that takes a string of braces, and determines if the order of the braces is valid. It should return true if ...
123 views

### Leetcode: Roman digit to integer

I tried to solve the question at https://leetcode.com/problems/roman-to-integer/ i.e Converting an Roman Digit to a Integer using C#. It passes all the test cases but any suggestions to reduce run ...
125 views

### HackerRank Equal Solution [closed]

Source: https://www.hackerrank.com/challenges/equal/problem Problem Description: Christy is interning at HackerRank. One day she has to distribute some chocolates to her colleagues. She is ...
89 views

### Minimum number of parentheses to be removed to make a string of parentheses balanced

The task: Given a string of parentheses, write a function to compute the minimum number of parentheses to be removed to make the string valid (i.e. each open parenthesis is eventually closed). ...
52 views

### Return a new array where each element is the number of smaller elements to the right of that element in the original input

The task: Given an array of integers, return a new array where each element in the new array is the number of smaller elements to the right of that element in the original input array. For ...
86 views

### Find duplicate in linear time and space

The task: You are given an array of length n + 1 whose elements belong to the set {1, 2, ..., n}. By the pigeonhole principle, there must be a duplicate. Find it in linear time and space. <...
48 views

### Code to find if a number fulfills certain requirements (e.g. sequential increasing, palindrome, repeating, etc)

I'm currently a 3rd year computer science student and lecturers have never checked the readability and maintainability of code. We were only marked on our outputs and as such I've written some truly ...
40 views

### Hackerrank Beautiful Strings

Problem Statement You are given a string, S , consisting of lowercase English letters. A string is beautiful with respect S to if it can be derived from S by removing exactly 2 characters. ...
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### Return whether a string is a palindrome if you can delete at most k elements

The task: Given a string which we can delete at most k, return whether you can make a palindrome. For example, given 'waterrfetawx' and a k of 2, you could delete f and x to get '...
57 views

### Rotate a list by k elements

The task: Write a function that rotates a list by k elements. For example, [1, 2, 3, 4, 5, 6] rotated by two becomes [3, 4, 5, 6, 1, 2]. Try solving this without creating a copy of the list. ...
52 views

### Leetcode: Detecting duplicate elements in an array within a k-element window

Upon solving the problem 'contain duplicates` in leetcode: Given an array of integers and an integer k , find out whether there are two distinct indices i and j in the array such that nums[i] = ...
88 views

### Sort a list using a reverse helper function

The task: Given a list, sort it using this method: reverse(lst, i, j), which reverses lst from ...
57 views

### Programming Challenge from Kattis: Distinctive Characters

I'm currently working on this problem from Kattis. In short, we're supposed to find the string that has the least similarity to any other string given. Every element of a string is either 0 or 1. ...
66 views

### Find the smallest distance between any two given words in a string

The task: Find an efficient algorithm to find the smallest distance (measured in number of words) between any two given words in a string. For example, given words "hello", and "world" and a ...
128 views

### Leetcode online Find the judge, graph with highest degree

Here is the problem. In a town, there are N people labelled from 1 to N. There is a rumor that one of these people is secretly the town judge. If the town judge exists, then: The town ...