Four Cells: An Introduction

Question

This is a Four Cells puzzle, an area-dividing puzzle.

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Rules of Four Cells:

• The grid is to be divided along the grid lines into areas containing exactly four cells.
• A number in a cell indicates how many of its four sides are segments of area boundaries. Note that this also includes the border of the grid.
• Line segments of area boundaries should not be left dangling. (See below for an example)
• An area may contain any multiple number cells (including none).

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An example grid is shown below for greater clarity.

Example puzzle:

Solution to example puzzle:

The example below showcases dangling ends and is an incorrect solution to the puzzle.

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Shown below is the actual puzzle to solve:

Good luck and have fun!

Answer 1

Some basic deductions:

Next, look at

the 3 in the center. It must be a "dead end" of a region; if it goes up, then it must go left then, and we have a problem -- we can't make the fourth cell without running into the top 2's region!
So the 3 doesn't go up, and R2C3 is a dead end. Making sure to keep regions of size 4, we get to here:

Now let's look at possibilities for another clue:

specifically, the 1 on the right. It has to be the middle cell of a T tetromino; if the tetromino is oriented as ��, ⊤, or ⊢, it will cut off the upper right corner. So it must be a ⊣.

And finally,

if the 3 region goes down and connects to the two cells below it, the cell in R6C3 will be blocked off. So it must make an S tetromino instead, and this completes the puzzle!