Pakkaus

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Objects;

/**
 *
 * @author Roni Juntunen
 */

public class Pakkaus {
    public static void main(String[] args) throws IOException {
        //Long time; //ajan testaamiseen vain debugaukseen
        //Scanner input = new Scanner(System.in);
        //String instr = input.nextLine(); //luetaan parametrit merkkijonoon
        char[] in;
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        String instr = r.readLine();
        in = instr.toCharArray();
        //time = System.currentTimeMillis();
        char[] out = new char[1000000]; //varataan muuttuja tulokselle
        Integer indexin = 0; //ilmaisee merkkijonon luennan sijainnin
        Integer indexout = 0; //ilmaisee merkkijonon ulostulon sijainnin
        String part = ""; //valiaikainen merkkijono kertoimen lukemiseen, tarvitaan yli kaksi merkkisiin kertoimiin
        Integer end = instr.length();
        Integer multiplier; //valmis kerroin
        String substring = ""; //toistettava merkkijono
        Boolean loop = true; //niin kauan kuin true, ohjelma pyorii
        while (loop){ //main loop
            while (Character.isDigit(in[indexin])){ //luetaan kerroin
                part += String.valueOf(in[indexin]);
                indexin++;
            }
            while (Character.isLetter(in[indexin])){ //luetaan merkkijono
                substring += String.valueOf(in[indexin]);
                indexin++;
                if (Objects.equals(indexin, end)){
                    loop = false;
                    break;
                }
            }
            multiplier = Integer.parseInt(part);
            //out[multiplier / end * 1000] += String.valueOf(new char[multiplier]).replace("\0", substring); //toistetaan merkkijono kertoimen mukaan
            char c[] = (String.valueOf(new char[multiplier]).replace("\0", substring)).toCharArray();
            System.arraycopy(c, 0, out, indexout, multiplier * substring.length());
            indexout += multiplier * substring.length();
            //String s = String.valueOf(new char[multiplier]).replace("\0", substring); //toistetaan merkkijono kertoimen mukaan
            //out += String.valueOf(new char[multiplier]).replace("\0", substring); //toistetaan merkkijono kertoimen mukaan
            //for (int i = 0; i < multiplier; i++) {
                //out = out + substring;
            //}
            part = "";
            substring = "";
            }
        Long time2 = System.currentTimeMillis();
        StringBuilder builder = new StringBuilder();
        for (char value : out) {
            builder.append(value);
        }
        //String text = builder.toString();
        System.out.println(builder.toString()); //tulostetaan tulos
        //System.out.println(Arrays.toString(out).replaceAll("\\W","")); //tulostetaan tulos
        //System.out.println(time2 - time); //tulostetaan aika
    }
}

Test 1

Group: 1

Verdict: WRONG ANSWER

Test 2

Group: 1

Verdict: WRONG ANSWER

Test 3

Group: 1

Verdict: WRONG ANSWER

Test 4

Group: 1

Verdict: WRONG ANSWER

Test 5

Group: 1

Verdict: WRONG ANSWER

Test 6

Group: 2

Verdict: WRONG ANSWER

Test 7

Group: 2

Verdict: WRONG ANSWER

Test 8

Group: 2

Verdict: WRONG ANSWER

Test 9

Group: 2

Verdict: WRONG ANSWER

Test 10

Group: 2

Verdict: WRONG ANSWER

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: WRONG ANSWER

Test 15

Group: 3

Verdict: WRONG ANSWER