description: It is a complicated version of problem F1. The difference between them is the constraints (F1: k ≤ 2, F2: k ≤ 10).
  
  You are given an integer n. Find the minimum integer x such that x ≥ n and the number x is k-beautiful.
  
  A number is called k-beautiful if its decimal representation having no leading zeroes contains no more than k different digits. E.g. if k = 2, the numbers 3434443, 55550, 777 and 21 are k-beautiful whereas the numbers 120, 445435 and 998244353 are not.
  
  Input
  
  The first line contains one integer t (1 ≤ t ≤ 10^4) — the number of test cases. Then t test cases follow.
  
  Each test case consists of one line containing two integers n and k (1 ≤ n ≤ 10^9, 1 ≤ k ≤ 10).
  
  Output
  
  For each test case output on a separate line x — the minimum k-beautiful integer such that x ≥ n.
  
  Example
  
  Input
  
  
  6
  2021 3
  177890 2
  34512 3
  724533 4
  998244353 1
  12345678 10
  
  
  Output
  
  
  2021
  181111
  34533
  724542
  999999999
  12345678
solution: import java.util.ArrayList;
  import java.util.Scanner;
  
  public class contestF {
      public static void main(String[] args) {
          Scanner scanner = new Scanner(System.in);
          int t = scanner.nextInt();
          while (t-- > 0) {
              String s = scanner.next();
              int k = scanner.nextInt();
              String ans = "";
              for(int i=0;i<s.length();++i) ans+='9';
              int cnt = 0;
              int[] mk = new int[10];
              for(int i=0;i<10;++i) mk[i] = -1;
              for(int i=0;i<s.length();++i){
                  int x = s.charAt(i) - '0';
                  // 0 change
                  String r0 = "";
                  for(int j=0;j<i;++j) r0+=s.charAt(j);
                  for(int j=x+1;j<10;++j) if(mk[j]!=-1){
                      r0+=j;
                      break;
                  }
                  for(int j=0;j<10;++j) if(mk[j]!=-1){
                      for(int l=i+1;l<s.length();++l) r0+=j;
                      break;
                  }
                  if(cnt<=k) ans = getMin(ans,r0);
                  // 1 change
                  String r1 = "";
                  for(int j=0;j<i;++j) r1+=s.charAt(j);
                  if(x<9) r1+=(x+1);
                  if(x<9 && mk[x+1]==-1){
                      for(int j=0;j<10;++j) if(mk[j]!=-1 || j==x+1){
                          for(int l=i+1;l<s.length();++l) r1+=j;
                          break;
                      }
                  }
                  else {
                      for(int l=i+1;l<s.length();++l) r1+="0";
                  }
                  if(cnt+1<=k) ans = getMin(ans,r1);
                  // 2 change
                  String r2 = "";
                  for(int j=0;j<i;++j) r2+=s.charAt(j);
                  if(x<9) r2+=(x+1);
                  for(int l=i+1;l<s.length();++l) r2+="0";
                  if(cnt+2<=k) ans = getMin(ans,r2);
  //                System.out.println(r0+" "+r1+" "+r2);
                  if(mk[x]==-1){
                      mk[x]=i;
                      cnt++;
                  }
              }
              if(cnt <= k) ans = getMin(ans,s);
              System.out.println(ans);
          }
      }
      static String getMin(String s,String t){
          if(s.length()!=t.length() || t.charAt(0)=='0') return s;
          for(int i=0;i<s.length();++i){
              if(s.charAt(i)<t.charAt(i)) return s;
              if(s.charAt(i)>t.charAt(i)) return t;
          }
          return s;
      }
  }
  