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: 609 ms):
import java.math.*;

import java.util.*;



public class Main {

static int N = (int)2e5 + 5;

static int[] a = new int[N];

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

int T = sc.nextInt();

while(T-- > 0){

String s = sc.next();

int len = s.length();

for(int i = 1;i <= len;i++){

a[i] = (int)s.charAt(i - 1) - (int)'0';

}

for(int i = 1;i <= len;i++){

int x = a[i], idx = i;

int mx = x, id = -1;

for(int j = i + 1;j <= len && j <= i + 8;j++){

if(a[j] - (j - i) > mx){

mx = a[j] - (j - i);

idx = j;

}

}

for(int j = idx - 1;j >= i;j--){

int t = a[j];

a[j] = a[j + 1] - 1;

a[j + 1] = t;

}

}

for(int i = 1;i <= len;i++){

System.out.print(a[i]);

}

System.out.println();

}

sc.close();

}

}