Solution to a special-shaped sudoku

Next, I argue that the squares marked in yellow must contain the same number. Whatever number goes in the bottom yellow square, that same number in row 5 can only be in the last square in the row. Column 3 is missing 4, 6, and 7. The yellow square on the right cannot contain 6 and 7. So the yellow square must contain 4.

When I solved it yesterday, the first 3 steps were the same as those given here, but after that I started working on the 4s. In the eighth row, the 4 can only go to the fourth square (R8C4), and after placing it, only the square R6C3 remains in the 6th row.

Now some easier moves. First in the picture with red color. The 6 inside the red square means that the number 6 must be in the last row R9C6 or R9C8. And therefore it must be in the 5th row (R5C3) in the third column. And then you can also write 7. Then look at the green colored number "4". They come quite easily. Then look at the blue colored number "3". They also come quite easily.

A very simple "7" is shown in Red . The 5 inside the Green box excludes the 5 in the topmost box in the 7th column. So only 7 can go in that box, and the "5" goes R5C7.

Next, 2 similar places are shown. Red are the variants marked in the leftmost figure "269". From there, the numbers "2" and "5" must be in either square of the U-shaped figure in the upper left corner (the small red numbers shown in the figure). The remaining 3 numbers in the first row are 1, 4 and 8. The box in the 8th column can only contain 4 of these numbers. Blue is an analogous situation on the right side, resulting in R9C2 in square number "3".

Next, some simpler moves. Red shows that the number "4" goes to R4C1 Green shows how to write 7, 1 and 8 in the first column Yellow shows a simple "8" in the first row. Purple shows that R7C9 is "3". Blue shows that all 7s can be placed.

Next, some easier moves. It is advisable to follow the order of colors Red can be used to fill in the middle shape 2 and 9 Green shows how to fill in the 4th column. Yellow can be used to fill in the number 2, as it is the only empty square in this shape. Purple shows in the lower right corner how to fill in the number 9 R8C2 and then R6C1. Blue shows how to fill in column 1 and then column 2.

From here on it's probably easier. As a hint, I'll say that R9C8 is "9" and then the bottom row gets number 6 and from there it's probably within everyone's reach.

It was an interesting task and solution. I went straight from step 1 to step 6.

I tried to put the solution here as simply as possible. Going from step 1 to step 6 is a very good way to solve the sudoku faster if you can notice it. I think I used some other option in the meantime that helped me. Later, when solving it, it turned out that it didn't have to be so complicated. But the sudoku itself is very well composed in my opinion. Quite an interesting second one.