Check if all lotto numbers are covered in input

Each ticket for the Pick-10 lotto has 10 unique numbers ranging from 1 to 99. Suppose you buy a lot of tickets and like to have them cover all numbers from 1 to 99. Write a program that reads the ticket numbers from a file and checks whether all numbers are covered. Assume the last number in the file is 0. Suppose the file contains the numbers:

80 3 87 62 30 90 10 21 46 27
12 40 83 9 39 88 95 59 20 37
80 40 87 67 31 90 11 24 56 77
11 48 51 42 8 74 1 41 36 53
52 82 16 72 19 70 44 56 29 33
54 64 99 14 23 22 94 79 55 2
60 86 34 4 31 63 84 89 7 78
43 93 97 45 25 38 28 26 85 49
47 65 57 67 73 69 32 71 24 66
92 98 96 77 6 75 17 61 58 13
35 81 18 15 5 68 91 50 76
0

Your program should display:

"The tickets cover all numbers"

Suppose the file contains the numbers

11 48 51 42 8 74 1 41 36 53
52 82 16 72 19 70 44 56 29 33
0

Your program should display:


"The tickets do not cover all numbers"

import java.util.Scanner;

    public class LottoCheck {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        //Create an array of booleans
        boolean[] neededNumbers = new boolean[99];

        //Prompt input
        System.out.println("Enter your ticket numbers: ");
        int ticketNumber = input.nextInt();

        while (ticketNumber != 0) {
            for (int i = 1; i <= neededNumbers.length; i++) {
                neededNumbers[i] = true;
            }
            ticketNumber = input.nextInt();
        }

        for (int i = 0; i < neededNumbers.length; i++) {
            if (neededNumbers[i] == false) {
                System.out.println("You do not have all the numbers.");
                System.exit(0);
            }
        }
        System.out.println("You have all the numbers.");
    }
    }

First, this will not work with the input 99. Arrays are 0-indexed, but when you create one, you need to specify the value you wish .length to have, which is 100.

This part is also erroneous:

while (ticketNumber != 0) {
    for (int i = 1; i <= neededNumbers.length; i++) {
        neededNumbers[i] = true;
    }
    ticketNumber = input.nextInt();
}

Here, you input the values until the input equals 0, but you loop from 1 through needeNumbers.length and set the values to true. First off, this will crash when you run it because the value neededNumbers[neededNumbers.length] does not exist. Additionally, your logic is wrong as you do not want all the values of neededNumbers to be set to true, just the input ones:

while (ticketNumber != 0) {
    neededNumbers[ticketNumber] = true;
    ticketNumber = input.nextInt();
}

This loop is almost right, but you check the value an index 0, which you did not set to true because 0 was the value to exit the loop:

for (int i = 0; i < neededNumbers.length; i++) {
    if (neededNumbers[i] == false) {
        System.out.println("You do not have all the numbers.");
        System.exit(0);
    }
}

You can solve this problem in one of two ways - starting with i = 1, or changing your while loop to use neededNumbers[ticketNumber - 1] = true; and intializing it to new boolean[99], like you currently do. This will have value 1 be stored in the 0 index of the array, so all values will be set to true once all the numbers in the range of 1 - 99 have been entered.

StackExchange Code Review Q#85134, answer score: 5