Programming Challenges 110106

Question

I am currently doing Problem 110106 from the programming challenges website. I am getting NoSuchElementException on the second 000 in the file below.

Below that is my code any help would be great.

Here's example:

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.NoSuchElementException;
import java.util.Scanner;

public class Problem110106 {

    int mainCounter = 0;
    int array[] = new int[10];

    public static void main(String[] args) throws FileNotFoundException, NoSuchElementException {
        // TODO Auto-generated method stub

        Problem110106 problem = new Problem110106();
        problem.start();
    }

    public void start() throws FileNotFoundException, NoSuchElementException {
        Scanner input = new Scanner(new BufferedReader(new FileReader("text.txt")));
        int numTestCases = Integer.parseInt(input.nextLine().trim());
        System.out.println(numTestCases);
        String blank = input.nextLine();
        System.out.println(blank);

        while (input.hasNext()) {

            int num = Integer.parseInt(input.next());
            if (input.next() == "") {

            } else {

                int first = num / 100;
                int second = (num / 10) % 10;
                int third = (num % 10);

                System.out.println(first);
                System.out.println(second);
                System.out.println(third);

                switch (first) {
                case 0:
                    break;
                case 1:
                    break;
                case 2:
                    set(first, second, third);
                    break;
                case 3:
                    add(first, second, third);
                    break;
                case 4:
                    multiply(first, second, third);
                    break;
                case 5:
                    set(first, second, third);
                    break;
                case 6:
                    add(first, second, third);
                    break;
                case 7:
                    multiply(first, second, third);
                    break;
                case 8:
                    set2(first, second, third);
                    break;
                }
            }
        }
    }

    public void set(int first, int second, int third) {
        array[second] = third;
        mainCounter++;
        // System.out.println("got here");
    }

    public void add(int first, int second, int third) {
        array[second] = array[second] + third;
        mainCounter++;
    }

    public void multiply(int first, int second, int third) {
        array[second] = array[second] * third;
        mainCounter++;
    }

    public void set2(int first, int second, int third) {
        // array[second] =
    }

    public void goTo() {
    }

}

Please indent your code properly. Nobody is going to read it as it is. — OldProgrammer, Jan 20 '14 at 17:55
Please state what your aim is. The algorithm might not be the right solution for the answer. — regulus, Jan 20 '14 at 17:56
Do they teach you how to [compare strings](http://stackoverflow.com/questions/513832/how-do-i-compare-strings-in-java) in Programming Challenges? — Paul Samsotha, Jan 20 '14 at 17:59

Joop Eggen · Answer 1 · 2014-01-20T20:27:36.870

0

while (input.hasNextInt()) {
    int num = Integer.parseInt(input.next());   
    if (!input.hasNext() || input.next().isEmpty()){
        break; // Jump out of the loop.
    } else {

Strings are normally compared as:

    input.next().equals("")

edited Jan 20 '14 at 20:27

answered Jan 20 '14 at 18:02

Joop Eggen

107,315
7
83
138

score 0 · Accepted Answer · answered Jan 20 '14 at 18:03

0

I think you problem may be here

while (input.hasNext()) {

      int num = Integer.parseInt(input.next());
      if (input.next() == "") {

The second line reads an input, but so does the next line. So when the loop is at the last element, the first line will read it, then the next line will try to read a next element that doesn't exist, hence NoSuchElementException.

And don't compare strings with ==. Use equals() or equalsIgnoreCase()

answered Jan 20 '14 at 18:03

Paul Samsotha

205,037
37
486
720

thank you, your solution fixed my problem. Also Ill witch to .equals() from now on :) – user2175076 Jan 20 '14 at 18:21

Programming Challenges 110106

2 Answers2