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Get StartedGiven a string, find all palindromic permutations of it… We know that the left and right half of a palindrome contains the same set of characters, so any palindromic permutations of a string are only possible if each character’s frequency in the string is even.
Given a line of text, reverse the text without reversing the individual words.
Given a string and an integer k, print the string in k rows in the zigzag form.
Find the length of the longest contiguous substring of a given string, such that the length of the substring is 2×n digits and the sum of the leftmost n digits is equal to the sum of the rightmost n digits.
Given a list of words, efficiently group all anagrams. The two strings, X and Y, are anagrams if by rearranging X’s letters, we can get Y using all the original letters of X exactly once.
Given a string, find first k non-repeating characters in it by doing only a single traversal of it.
Given a list of words and a pattern, find all words in the list that follows the same order of characters as that of the pattern.
Given two strings, determine whether they are isomorphic. Two strings, X and Y, are called isomorphic if all occurrences of each character in X can be replaced with another character to get Y and vice-versa.
Given a binary pattern containing ? wildcard character at a few positions, find all possible combinations of binary strings that can be formed by replacing the wildcard character by either 0 or 1.
Given a positive number, convert the number to the corresponding Excel column name.
Given a string, find the maximum length contiguous substring of it that is also a palindrome.
Given a string, check if it is a rotated palindrome or not. For example, CBAABCD is a rotated palindrome as it is a rotation of palindrome ABCDCBA.