#Language - C#
#Below program can store all the least occuring characters in a string.
#Time Complexity - O(N)
Created list to store the east occuring characters in a string and initialized temporary variable value to 1 (any character in string can occur at minimun once).
Iterated string and got the count of character using LINQ.
If the count of the character is less than or equal to temp variable, assign the count value to temp varibale and add that character to list.
public class Test
public static void Main()
string s =Console.ReadLine().ToLower();
List<char> list = new List<char>();
char c =' ';
int j = s.Where(t => t.Equals(s[i])).Count();
foreach(var v in list)