CODEWITHSUNDEEP
javaarrays
Israel Agbaeze
Israel Agbaeze

Reputation: 3

Processing the rows of a 2D array of ints

thanks in advance for your help. I'm new to java and I've been having difficulty processing the rows of a 2D array of ints. I've searched through this forum and other resourceful places, but nothing was helpful enough.

Here are the array elements:

1 2 3 4

4 9 17 26

2 4 6 8

1 3 5 7

9 12 32 33

4 8 10 16

3 7 9 21

10 11 12 13

here is my incorect code:

for (int row=0; row<list.length; row++) {
    for (int col=0; col<list[row].length; col++) {
        if (list[row][0] + 1 != list[row][1] && 
                list[row][1] + 1 != list[row][2] &&
                list[row][2] + 1 != list[row][3]) {

            System.out.print(list[row][col] + " ");
        }

    }
    System.out.println()

I need a code that can test and print the rows of the array whose elements are NOT consecutively incremented by 1, such as 1 2 3 4 and 10 11 12 13, assuming you do not know the values of the elements of the array.

Upvotes: 0

Views: 50

Answers (1)

Ricardo Costeira
Ricardo Costeira

Reputation: 3331

You can iterate through the whole column, compare each value, and use a boolean to keep track if they're consecutively incremented or not. Something like this:

boolean rowIsConsecutive;
int previousValue;

for (int row = 0; row<list.length; row++) 
{
  rowIsConsecutive = true;
  previousValue = list[row][0]; // This will blow up with a 1D array. Just wrote it like this for readability. 

  for (int col = 1; col<list[row].length && rowIsConsecutive; col++) 
  {
    if (list[row][col] == previousValue + 1) 
    {
      previousValue = list[row][col];
    }
    else 
    {
      rowIsConsecutive = false;
    }
  }

  if (rowIsConsecutive)
  {
    System.out.println(Arrays.toString(list[row]));
  }
}

Disclaimer: I didn't test this, but something along these lines should work. And I leave it to you to come up with a more performant way to do it :)

Upvotes: 1

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