I make a tetris game where i need to clear lines. I collect the full rows and make them empty by doing:

    for (var i = 0; i < playingGrid.Length; i  ) //get rows
    {
        if (!playingGrid[i].Contains(0)) //check if all colls are filled 
        {
            playingGrid[i] = new int[10]; //make the row empty
                                          //Here i need to push this row to the top of the jagged array

        }
    }
//playingGrid:
    public int[][] playingGrid = new int[20][];
  
for (var i = 0; i < 20; i  )
  {
    playingGrid[i] = new int[10];
  }

My question is how can i get the row that i cleared at the top of the jagged array?

CodePudding user response：

You should play with indexes to move full rows. Also, no need to use int array as the cell (column) can have only 2 states which is the perfect case for using bool:

var rowsCount = 20;
var columnsInRowCount = 10;

var playingGrid = new bool[rowsCount][];

for (var rowIndex = 0; rowIndex < playingGrid.Length; rowIndex  )
{
    playingGrid[rowIndex] = new bool[columnsInRowCount];
}

var rowIndexesToMove = new List<int>(rowsCount);
var firstNonEmptyRowIndex = Array.FindIndex(playingGrid, row => row.Contains(true));

// save full row indexes (start from first non-empty one, no need to check top empty rows)
for (var rowIndex = firstNonEmptyRowIndex; rowIndex < playingGrid.Length; rowIndex  )
{
    var row = playingGrid[rowIndex];

    if (!row.Contains(false))
    {
        rowIndexesToMove.Add(rowIndex);
    }
}

// move full rows to top
for (var fullRowIndex = 0; fullRowIndex < rowIndexesToMove.Count; fullRowIndex  )
{
    for (var rowIndex = rowIndexesToMove[fullRowIndex]; rowIndex >= firstNonEmptyRowIndex   fullRowIndex; rowIndex--)
    {
        for (var c = 0; c < playingGrid[firstNonEmptyRowIndex   fullRowIndex].Length; c  )
        {
            playingGrid[rowIndex][c] = false;
        }

        if (rowIndex > 0)
        {
            var temp = playingGrid[rowIndex];
            playingGrid[rowIndex] = playingGrid[rowIndex - 1];
            playingGrid[rowIndex - 1] = temp;
        }
    }
}