Problem: 2050D - Digital string maximization
Language: java

Solution 1 (runtime: 343 ms):
import java.util.*;



public class Main {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

int t = sc.nextInt();



while (t-- > 0) {

char[] sb = sc.next().toCharArray(); // Using char array for efficiency

int n = sb.length;



int index = 1;

while (index < n) {

if (sb[index] != '0') {

int toPlace = index - 1;

int subtract = 1;



while (toPlace >= 0 && (sb[index] - '0') - subtract > (sb[toPlace] - '0')) {

if (toPlace == 0) break;

toPlace--;

subtract++;

}



if ((sb[index] - '0') - subtract <= (sb[toPlace] - '0')) {

toPlace++;

subtract--;

}



if (toPlace != index) {

char res = (char) ((sb[index] - '0' - subtract) + '0');



// Shift elements manually instead of using `add()` and `remove()`

for (int j = index; j > toPlace; j--) {

sb[j] = sb[j - 1];

}

sb[toPlace] = res;

}

}

index++;

}



System.out.println(new String(sb)); // Fast output

}

}

}



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();

}

}