Problem: 2050D - Digital string maximization
Language: java

Solution 1 (runtime: 312 ms):
import java.io.*;

import java.util.*;



public class Main{

    public static void main(String[] args) throws Exception {

        if (System.getProperty("ONLINE_JUDGE") == null) {

            System.setIn(new FileInputStream("input.txt"));

            System.setOut(new PrintStream(new FileOutputStream("output.txt")));

        }



        FastReader sc = new FastReader();

        PrintWriter out = new PrintWriter(System.out);



        int t = sc.nextInt(); 

        //template

        while (t-- > 0) {

            String num = sc.next();

            int[] nums = new int[num.length()];

            int idx=0;

            while(idx<num.length()){

                nums[idx] = num.charAt(idx)-'0';

                idx++;

            }

            for(int i=1;i<num.length();i++){

                idx=i;

                while(idx>=1&&nums[idx-1]+1<nums[idx]&&nums[idx]>0){

                    int val = nums[idx];

                    nums[idx]=nums[idx-1];

                    nums[idx-1]=val-1;

                    idx--;

                }

                //System.out.println(Arrays.toString(nums));

            }

            StringBuilder sb = new StringBuilder();

            for(int i:nums)sb.append(i);

            System.out.println(sb);

        }



        out.flush(); 

    }



    // Optimized Fast Input Reader

    static class FastReader {

        BufferedReader br;

        StringTokenizer st;



        public FastReader() {

            br = new BufferedReader(new InputStreamReader(System.in));

        }



        String next() {

            while (st == null || !st.hasMoreElements()) {

                try {

                    st = new StringTokenizer(br.readLine());

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

            return st.nextToken();

        }



        int nextInt() {

            return Integer.parseInt(next());

        }



        long nextLong() {

            return Long.parseLong(next());

        }



        double nextDouble() {

            return Double.parseDouble(next());

        }



        String nextLine() {

            String str = "";

            try {

                str = br.readLine();

            } catch (IOException e) {

                e.printStackTrace();

            }

            return str;

        }

    }

}

class Pair<K,V>{

    K key;

    V value;

    public Pair(K key,V value){

        this.key=key;

        this.value=value;

    }

    public K getKey(){

        return this.key;

    }

    public V getValue(){

        return this.value;

    }

}

Solution 2 (runtime: 234 ms):
import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.StringTokenizer;



public class round991 {

static class Pair implements Comparable<Pair>{

int a;

long b;

String str;



Pair(int a,long b,String str){

this.a=a;

this.b=b;

this.str=str;

}



public int compareTo(Pair o) {

return Integer.compare(this.a, o.a); // Ascending order by a

}

//

//            public int compareTo(Pair o){

//                return Long.compare(this.b,o.b);

//            }

//

//            public int compareTo(Pair other) {

//                return this.str.compareTo(other.str); // Ascending order by str

//            }

//

}

static class FastReader {

BufferedReader br;

StringTokenizer st;



public FastReader() {

br = new BufferedReader(

new InputStreamReader(System.in));

}



String next() {

while (st == null || !st.hasMoreElements()) {

try {

st = new StringTokenizer(br.readLine());

} catch (IOException e) {

e.printStackTrace();

}

}

return st.nextToken();

}



int nextInt() {

return Integer.parseInt(next());

}



long nextLong() {

return Long.parseLong(next());

}



double nextDouble() {

return Double.parseDouble(next());

}



String nextLine() {

String str = "";

try {

if (st.hasMoreTokens()) {

str = st.nextToken("\n");

} else {

str = br.readLine();

}

} catch (IOException e) {

e.printStackTrace();

}

return str;

}

}

static ArrayList<Integer>[] gr;

public static void main(String[] args) {

FastReader sc = new FastReader();

PrintWriter out=new PrintWriter(System.out);

int t = sc.nextInt();

while (t != 0) {

t--;

String str=sc.next();

int[] arr=new int[str.length()];

for (int i = 0; i < arr.length; i++) {

arr[i]=str.charAt(i)-'0';

}

StringBuilder ans=new StringBuilder("");

for (int i = 0; i < arr.length; i++) {

int dig=arr[i];

int j=i-1;

while (j>=0 && arr[j]<dig-1){

arr[j+1]=arr[j];

--dig;

arr[j]=dig;

--j;

}

//                out.println(st);

}

//            out.println(Arrays.toString(arr));

for (int num:arr) {

ans.append(""+num);

}

out.println(ans);

}

out.flush();

}

}