Given two strings str1 and str2 of size m and n, write a program to check whether the two strings are an anagram of each other or not. A string str1 is an anagram of str2 if the characters of str1 can be rearranged to form str2.

Write a program to find the length of the longest substring without repeating characters. Substring is the continuous sub-part of the string. The aim is to determine the maximum such subpart which has all the unique characters.

Given a string S[], write a program to sort it in decreasing order based on the frequency of the characters. The frequency of a character is the number of times it appears in the string. If two characters have the same frequency, whichever occurs earliest in S, must come first. In other words, the sorting must be stable.

The longest common subsequence algorithm is a problem to find the length of the longest subsequence common to all subsequences of two strings. The lcs algorithm differs from the algorithm of the longest common substring problem. Explore and Enjoy!

Given a Roman numeral, write a program to find its corresponding decimal value. Roman numerals are represented by seven different symbols: I , V, X, L, C, D and M.