Question

I am just wondering if anyone could show me some code as to how I would put this string in a 2D boolean array and print it out

Example: “0-1 0-2 1-2 1-3 2-3” , however the string could be more complicated like this “0-1 1-2 2-3 3-0 0-4 0-11 1-5 1-6 2-7 2-8 3-9 3-10 4-5 6-7 8-9 10-11 4-7 4-8 5-9 5-10 6-9 6-10 7-11 8-11”

An example would be 0-1 is true, 0-2 is true, 1-2 is true, 1-3 is true, 2-3 is true, all other postions should be false

Answer 1

I don’t know what you mean by putting them in a 2D boolean array. If you have problem with parsing the text, then here are some snippet of code you can use.

For the first solution, I assume that the numbers always come in pairs and are separated by a single -, and space is used to delimit between the pairs of numbers.

Use this if you are reading from standard input:

Scanner scanner = new Scanner(System.in);

Use this if you have a String contains all the numbers and you want to process it (let the name of the variable be inputString):

Scanner scanner = new Scanner(inputString);

Then you can read the numbers from the input:

while (scanner.hasNext()) {
    String pair = scanner.next();
    // Split by the hyphen
    String tokens[] = pair.split("-");

    // Normally, one should check the array before accessing it
    // I currently assume the input is valid
    int first = Integer.parseInt(tokens[0]);
    int second = Integer.parseInt(tokens[1]);

    // Do whatever you want with the 2 numbers extracted
}

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Alternatively, you can also use useDelimiter to add - as delimiter and use nextInt to read number without having to deal with - separately:

scanner.useDelimiter("[\\p{javaWhitespace}-]+");

The code will simply becomes:

scanner.useDelimiter("[\\p{javaWhitespace}-]+");

while (scanner.hasNext()) {
    int first = scanner.nextInt();
    int second = scanner.nextInt();

    // Do whatever you want with the 2 numbers extracted
}

The code is cleaner, but whether - appear between first and second, or how many - appear, or is it the only character between the pair of numbers not is not known now. It is OK if we assume the input format is correct. However, if that assumption is not given, we can’t do any input validation.