Amanda has a string of lowercase letters that she wants to copy to a new string. She can perform the following operations with the given costs. She can perform them any number of times to construct a new string : Append…
Given two strings, determine if they share a common substring. A substring may be as small as one character. For example, the words "a", "and", "art" share the common substring . The words "be" and "cat" do not share a…
We consider two strings to be anagrams of each other if the first string's letters can be rearranged to form the second string. In other words, both strings must contain the same exact letters in the same exact…
Two words are anagrams of one another if their letters can be rearranged to form the other word. In this challenge, you will be given a string. You must split it into two contiguous substrings, then determine the…
Given a string of lowercase letters in the range ascii[a-z], determine a character that can be removed to make the string a palindrome. There may be more than one solution, but any will do. For example, if your string…
James found a love letter that his friend Harry has written to his girlfriend. James is a prankster, so he decides to meddle with the letter. He changes all the words in the letter into palindromes. To do this, he…
Alice has a binary string. She thinks a binary string is beautiful if and only if it doesn't contain the substring . In one step, Alice can change a to a or vice versa. Count and print the minimum number of steps needed…
You are given a string containing characters and only. Your task is to change it into a string such that there are no matching adjacent characters. To do this, you are allowed to delete zero or more characters in the…
John has collected various rocks. Each rock has various minerals embeded in it. Each type of mineral is designated by a lowercase letter in the range . There may be multiple occurrences of a mineral in a rock. A mineral…
Steve has a string of lowercase characters in range ascii[‘a’..’z’]. He wants to reduce the string to its shortest length by doing a series of operations. In each operation he selects a pair of adjacent lowercase…
In this challenge, you will determine whether a string is funny or not. To determine whether a string is funny, create a copy of the string in reverse e.g. . Iterating through each string, compare the absolute…
Roy wanted to increase his typing speed for programming contests. His friend suggested that he type the sentence "The quick brown fox jumps over the lazy dog" repeatedly. This sentence is known as a pangram because it…
We say that a string contains the word hackerrank if a subsequence of its characters spell the word hackerrank. For example, if string it does contain hackerrank, but does not. In the second case, the second r is…
Sami's spaceship crashed on Mars! She sends a series of SOS messages to Earth for help. Letters in some of the SOS messages are altered by cosmic radiation during transmission. Given the signal received by Earth as a…
Alice wrote a sequence of words in CamelCase as a string of letters, , having the following properties: It is a concatenation of one or more words consisting of English letters. All letters in the first word are…
You are given a square map as a matrix of integer strings. Each cell of the map has a value denoting its depth. We will call a cell of the map a cavity if and only if this cell is not on the border of the map and each…
You are the benevolent ruler of Rankhacker Castle, and today you're distributing bread. Your subjects are in a line, and some of them already have some loaves. Times are hard and your castle's food stocks are dwindling…
Lisa just got a new math workbook. A workbook contains exercise problems, grouped into chapters. Lisa believes a problem to be special if its index (within a chapter) is the same as the page number where it's located…
Calvin is driving his favorite vehicle on the 101 freeway. He notices that the check engine light of his vehicle is on, and he wants to service it immediately to avoid any risks. Luckily, a service lane runs parallel to…
Little Bobby loves chocolate. He frequently goes to his favorite store, Penny Auntie, to buy them. They are having a promotion at Penny Auntie. If Bobby saves enough wrappers, he can turn them in for a free chocolate…
