Bigger is Greater.cs

using System;
using System.Collections.Generic;
using System.IO;
class Solution {
    static void Main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution */
        int t = int.Parse(Console.ReadLine());
        while(t-- > 0){
            char[] chr = Console.ReadLine().Trim().ToCharArray();
            int len = chr.Length;
            bool poss = false;
            int[] pos = new int[26];
            int idx = -1;
            int w = -1;
            bool[] small = new bool[26];
            small[(int)chr[len-1] - (int)'a'] = true;
            pos[(int)chr[len-1] - (int)'a'] = len - 1;
            for(int i = len - 2 ; i >= 0 ; i--){
                int acode = (int)chr[i] - (int)'a';
                for(int j = acode + 1; j < 26 ; j++){
                    
                    if(small[j])
                        {
                        poss = true;
                        idx = pos[j];
                        break;
                    }
                }
                if(poss){
                    w = i ;
                    break;
                }
                small[acode] = true;
                pos[acode] = i;
            }
            //Console.WriteLine(w + "-" + idx);
            if(poss){
                char c = chr[w];
                chr[w] = chr[idx];
                chr[idx] = c;
                char[] sortarr = new char[len - w - 1];
                int counter = 0 ;
                for(int i = w + 1 ; i < len ; i++){
                    sortarr[counter] = chr[i];
                    counter++;
                }
                Array.Sort(sortarr);
                for(int i = 0 ; i < sortarr.Length ; i++){
                    chr[w + 1] = sortarr[i];
                    w++;
                }
                Console.WriteLine(new string(chr));
            } else {
                Console.WriteLine("no answer");
            }
        }
    }
}