Data free response answer 2022

Data is #4 from the from the 2022 AP Computer Science A Free Response problems.

https://apcentral.collegeboard.org/pdf/ap22-frq-computer-science-a.pdf?course=ap-computer-science-a

Part (a) repopulate method

public void repopulate()
{
    for(int r = 0; r < grid.length; r++)
    {
        for(int c = 0; c < grid[0].length; c++)
        {
            int rand = (int) (Math.random() * MAX) + 1;
            while(rand % 10 != 0 || rand % 100 == 0)
                rand = (int) (Math.random() * MAX) + 1;
  
            grid[r][c] = rand;
        }
    }
}

For more on working with Math.random() see Generating numbers with Math.random().

Part (b) countIncreasingCols method

public int countIncreasingCols()
{
    int increasingCols = 0;

    for(int c = 0; c < grid[0].length; c++)
    {
        boolean isIncreasing = true;

        for(int r = 1; r < grid.length; r++)
            if(grid[r-1][c] > grid[r][c])
                isIncreasing = false;

        if(isIncreasing)
            increasingCols++;
    }

    return increasingCols;
}

2022 AP CS Exam Free Response Solutions

Additional 2D array resources

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