Longest Uncommon Subsequence

// C# program to find longest 
// uncommon subsequence using
// naive method
using System;
using System.Collections.Generic;

class GFG
{     
    // function to calculate 
    // length of longest
    // uncommon subsequence
    static int findLUSlength(string a, 
                             string b)
    {
        // creating an unordered 
        // map to map strings to
        // their frequency
        Dictionary<string, int> map = 
                   new Dictionary<string, int>(); 
        List<string> strArr =
                 new List<string>();
        strArr.Add(a);
        strArr.Add(b);
    
        // traversing all elements
        // of vector strArr
        foreach (string s in strArr)
        {
            // Creating all possible
            // subsequences, i.e 2^n
            for (int i = 0; 
                     i < (1 << s.Length); i++) 
            {
                string t = "";
                for (int j = 0; 
                         j < s.Length; j++) 
                {
    
                    // ((i>>j) & 1) determines 
                    // which character goes 
                    // into string t
                    if (((i >> j) & 1) != 0) 
                        t += s[j];
                }
    
                // If common subsequence 
                // is found, increment 
                // its frequency
                if (map.ContainsKey(t))
                {
                    int value = map[t] + 1;
                    map.Remove(t);
                    map.Add(t, value);
                }
                else
                    map.Add(t, 1);
            }
        }
        int res = 0;
        foreach (KeyValuePair<string, int> 
                             entry in map)
        // traversing the map
        {
            // if frequency equals 1 
            if (entry.Value == 1)
                res = Math.Max(res,
                           entry.Key.Length); 
        }
        return res;
    } 
    
    // Driver code
    static void Main () 
    { 
        
        // input strings
        string a = "abcdabcd",
               b = "abcabc"; 
        
        Console.Write(findLUSlength(a, b));
    }
}

// This code is contributed by 
// Manish Shaw(manishshaw1)

// C# program to find longest uncommon
// subsequence using naive method.
using System;

class GfG {
    
    // function to calculate length
    // of longest uncommon subsequence
    static int findLUSlength(String a, String b)
    {
        
        // Case 1: If strings are equal
        if (a.Equals(b)==true) 
            return 0;
    
        // for case 2 and case 3
        return Math.Max(a.Length, b.Length);
    }
    
    // Driver code
    public static void Main ()
    {

        // input strings
        String a = "abcdabcd", b = "abcabc"; 
        Console.Write(findLUSlength(a, b));
    }
}

// This code is contributed by nitin mittal.

using System;
using System.Collections.Generic;

class GFG {
    // Helper function to check if two sets are equal
    static bool areSetsEqual(HashSet<char> set1,
                             HashSet<char> set2)
    {
        if (set1.Count != set2.Count) {
            return false;
        }
        foreach(char item in set1)
        {
            if (!set2.Contains(item)) {
                return false;
            }
        }
        return true;
    }

    static int find_lus_length(string s1, string s2)
    {
        // Create sets of characters in s1 and s2
        HashSet<char> set1 = new HashSet<char>(s1);
        HashSet<char> set2 = new HashSet<char>(s2);

        // If the sets are equal, return -1
        if (areSetsEqual(set1, set2)) {
            return -1;
        }
        else {
            // Otherwise, return the maximum length of s1
            // and s2
            return Math.Max(s1.Length, s2.Length);
        }
    }

    // Driver Code
    static void Main(string[] args)
    {
        string s1 = "abcdabcd";
        string s2 = "abcabc";
        Console.WriteLine(find_lus_length(s1, s2));
    }
}