String Algorithms

Generating IP Addresses [Backtracking String problem]

In this article, we will explore a common problem of restoring IP addresses from a given string of digits. For example, given the string "25525511135", the valid IP addresses that can be generated are "255.255.11.135" and "255.255.111.35".

String Algorithms

String isomorphism

In this article, we will learn about string isomorphism and algorithms to solve this problem efficiently.

Algorithms

Scramble String problem

We will be given two strings a, and b we have to check whether one string is scrambled version of other string or not.

String Algorithms

Power Set of String in Lexicographic order

In this article, we have explored what is the meaning of Power Set of String and the algorithm to generate Power Set of String in Lexicographic order.

String Algorithms

Minimum Window Substring

Given two strings A and B. We need to find the smallest substring of A that has all the characters in B. If there is no such string, then the answer will be an empty string.

String Algorithms

N-th Permutation of a string

Given a string of length of `m` containing only lowercase alphabets. Find out the lexicographic `nth` permutation of the given string.

String Algorithms

Lexicographic next string

In this article, we are going to find the lexicographic next string for the given string.

Algorithms

First K maximum occurring words

In this article, we will understand the different approaches to return the first k maximum occurring words from a given array. It includes core Data Structures and Algorithm topics such as Arrays, HashMap, Sorting, Priority Queue and Heap, Trie, and Bucket sort.

String Algorithms

Check if a string can be convert to another by swapping two characters

Having two strings s1 and s2 equal in length of size n, you must check if they are equal after you swap any of two different characters. If strings are different on more than just 2 characters it must return false.

Algorithms

Longest word with given prefix and suffix

You are given a list of words, a prefix, and a suffix. You have to find the longest word in the given word list that has a given prefix and suffix.

String Algorithms

Lexicographic rank of string

We will see what is the rank of the string in lexicographic order, for the words which can be made using all the characters of the given string and calculate using a string algorithm.

trie

Longest word in dictionary with all prefixes

Given a list of words ‘WORDLIST’, find the longest perfect word. A perfect word is a word in which all the possible prefixes are present in ‘WORDLIST’.

String Algorithms

Find permutations of string in lexicographic order

In this article, we have presented an algorithm to Find permutations of string in lexicographic order. We have used the concept of Recursion.

Algorithms

Number of Substrings in String of 0s and 1s that have K 1s

In this article, we have explored algorithm to find the Number of Substrings in a String of 0's and 1's that have 'K' number of 1's.

String Algorithms

Find all anagrams of a given string

In this article, we have explained efficient algorithms to Find all anagrams of a given string. This involve techniques like sliding window approach.

Data Structures

Persistent Trie

In this article, we discuss the Trie data structure and how to make it persistent to solve various problems optimally.

Algorithms

Longest Substring with at Least K repeating characters

In this article, we have presented two algorithms to find the Longest Substring with at Least K repeating characters.

Algorithms

Maximum String Partition problem: Partition Labels

In this article, we have explored approaches to solve the maximum string partition problem (Partition Labels) efficiently.

Algorithms

Substring with Concatenation of All Words

In this article, we have explained two approaches to solve the problem Substring with Concatenation of All Words. This involves the idea of Hash Map and Two Pointer.

Algorithms

ZigZag Conversion of String with N rows

In this article, we have solved the problem of ZigZag Conversion of String with N rows. We take a string and a number N (rows) as input and distribute the string in ZigZag fashion among N rows and print the final string.

Algorithms

Longest Common Prefix

In this article, we are going to explore different approaches to find the longest common prefix between two strings. Same techniques can be applied to find the Longest Common Prefix for multiple strings.

Algorithms

Longest substring without repeating characters

In this article, we have explained three approaches to the problem of finding Longest substring without repeating characters. This involves the use of Hash Map with the clever use of start and end index.

Algorithms

Longest Common Suffix Problem

In this article, we will see how we can find the longest common suffix (i.e ending) that all the strings given to us have. We shall start with the brute-force approach for two strings. Following this, we will implement the Trie data structure to solve the problem for more than two strings.

Algorithms

Deleting Duplicate Characters of String

We have explored the problem of Deleting Duplicate Characters of String such that the resulting string is lexicographically the smallest among all possibilities.

Algorithms

Number of sub-strings with each character occurring even times

This article discusses different algorithmic approach which we can use to find number of sub-strings with each character in it occurring even number times for a given string.