using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace SoloLearn { class Program { //this array holds the order used to sort a string, changing the // order of charachters in this array changes the sorting results // removing any char from this array will ignore it in the result static char[] allChars = {'!','@','#','$','%','^','&','*','(',')','_','-','+','=','1','2','3','4','5','6','7','8','9','0','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'}; ////////////// //Algorithm // ////////////// /* 1- all chars of string are transfered to a char list if a char is not contained in the array(allChars) it is ignored 2- the list of chars is sorted using selection sort algorithm 3- chars are printed to the console */ static void SortString(string str) { List chars = GetChars(str); SortChars(chars); PrintSortedChars(chars); } static List GetChars(string str) { int n = str.Length; List result = new List(n); for(int i = 0 ; i < n ; i++) { char chr = str[i]; if(allChars.Contains(chr)) { result.Add(chr); } } return result; } static int CompareChars(char firstChar, char secondChar) { int firstIndex = Array.IndexOf(allChars,firstChar); int secondIndex = Array.IndexOf(allChars,secondChar); if(firstIndex > secondIndex) { return 1; } else { return -1; } } static void SortChars (List chars) { int n = chars.Count; for(int i = 0 ; i < n-1 ; i ++) { int minIndex = i ; for(int j = i+1; j < n ; j++ ) { if(CompareChars(chars[minIndex],chars[j]) == 1) { minIndex = j ; } } // swapping the values at index i and minIndex char temp = chars[minIndex]; chars[minIndex] = chars[i]; chars[i] = temp; } } static void PrintSortedChars(List chars) { int n = chars.Count; Console.Write("{"); for(int i = 0 ; i < n ; i++) { Console.Write(chars[i]); if(i!=n-1) { Console.Write(","); } } Console.WriteLine("}"); } static void Main(string[] args) { string str = Console.ReadLine().ToLower(); Console.WriteLine("original string: "+str); SortString(str); Console.WriteLine("Test Code: "); Console.WriteLine("==========="); string str1 = " "; Console.WriteLine(str1); SortString(str1); Console.WriteLine("==========="); string str2 = "hello worlds 11 hi ho 22"; Console.WriteLine(str2); SortString(str2); Console.WriteLine("==========="); string str3 = "hello How $are you 11$$&&"; Console.WriteLine(str3); SortString(str3); } } }

Sorting a String