Java how to check if a row is empty in a 2d array.

Question

Let's say I have a 2d array (G) that looks like this: ``` 0 0 0 0 0 12 13 0 0 0 6 0 0 0 0 3 0 6 0 4 0 0 0 5 0 0 4 0 10 0 0 7 0 0 0 10 0 11 8 9 12 0 0 0 11 0 1 0 13 0 0 0 8 1 0 2 0 3 5 7 9 0 2 0 ``` I have to traverse an array like this and find the minimum value that's not zero. After I find the minimum value I add it to another 2d array called H which is empty but has the same size as G. Once I add the value to H I then set the value in G to zero and traverse though the array again to find the 2nd smallest value, then the 3rd, then the 4th and so on. I stop traversing the array when every single line in H has a value in it. So for the above array, on my first pass I would find 1 to be the lowest value so I add it to H like this: ``` 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 ``` Here's what I wrote in java: ``` int numVerts = G.length; int [][] H = new int[numVerts][numVerts]; while (/*there exists a…

Accepted Answer

You do not want to traverse through H again. So you have to somehow store the rows of H in which you put a new value.

You could make a boolean array the size of the number of rows in H. Then after each time you add something to H you set the value for the row to true in the boolean array. Then you iterate through the boolean array and see if a value is still false. If this is not the case you are finished.

Java how to check if a row is empty in a 2d array.

Solution

Problem