# How to Solve Sudoku by Techniques of Champions (Part 4)

So, we have finished filling 6 of the 9 squares in the game grid. Now we have to deal with those empty cells in squares #2, #3 and #8.

How to play Sudoku next? Let's look at the top row of squares. We are interested in the second row, which turned out to be well filled: 7, 2, 8, 3, 4 and 9. That is, we have six numbers out of nine. That's good. All that remains is to figure out where to put the missing 1, 5 and 6.

Pay attention to the six. It is in the square in the center (bottom row, where 4-6-8) and in the right column (1-9-3-4-7-8). So, by the method of elimination we understand that 6 in this case will be placed only in the penultimate empty cell of the row (i.e. in the center of square #3).

The second line has been transformed. It now contains 7-2-8-3-pobel-4-9-pobel-6. It remains to figure out how to find a place for 1 and 5. Let's go down (look at the columns) and see that the center column already has a 5 (3-2-6-8-8-4-5). Accordingly, we can place only 1 in the center of square #2. The five is "asked" to the end of the second row. Thus, the line looks like 7-2-8-3-1-4-9-9-5-5-6.

After filling the second line from above, it becomes easier to work with squares (and not only).

Hanging fruit is back in business

So square #3 on the top right is almost full. It has 4-1-space-9-6-5-5-7-7-3-space. I.e. we can see that the numbers 2 and 8 are missing. By analyzing the squares and rows, we can see that we can't find room for the twos and eights yet.

That's all right! No luck with the squares? Let's look at rows and columns! We need the hanging fruit technique again, where we look for the simplest areas. Let's look at what's happening in square #2 in the center column. It looks like 1-3-2-6-6-8-8-4-5. This means we need to fit the remaining 7 and 9 into the column. We look at the top horizontal line and see that there is already a 9 there (5-3-9-propel-propel-propel-propel-propel-4-1-propel).

Accordingly, we insert the 7 at the top center of square #2, and move the 9 down. Thanks to this move we have almost finished square #2. It looks like space-7-space-3-1-1-4-space-9-space. We realize by the method of elimination that there should be values 2, 5, 6 and 8 in square #2. We analyze what numbers are next to each other. For example, it immediately catches our eye that 5 is on the top row of square #1. Accordingly, we can put 5 only in the bottom row of square #2. But in which cell: to the right or to the left of the nine? The lower right corner of square #2 doesn't fit: the five is in column 3-5-7-4-4-1-9. Accordingly, the 5 can only be placed in the lower right corner of square #2.

So, we have filled 6 squares using the "hanging fruit" and "exception" techniques. There are 7 empty cells left. the problem is that "getting to them" is difficult.

At this point, there are only 7 gaps left. But unfortunately, we can't fill them in because several identical numbers confuse us.

К примеру, справа вверху (квадрат №3) можно поставить или 2, или 8. Но на основе анализа верхней строки и крайнего левого столбца нельзя понять, какое значение подходит больше.

Хорошо, пока оставим. Попробуем поработать с квадратом №2, где на данный момент находятся значения 7, 3, 1, 4, 9 и 5. Соответственно, нам нужно вписать 2, 6 и 8. Но пока нельзя понять, как и куда именно. Проблема в том, что в квадрате №3 тоже нет 2 и 8. Внизу по центру (квадрат №8) также не хватает 2 и 6.

Что делать в такой ситуации и как получить подсказку? Если на бумаге обычно писали число мелким шрифтом, как бы «пристреливаясь» в ситуации, то онлайн-играх есть специальные инструменты вроде «Проверка решения».

К примеру, хотим попробовать разместить цифру 2. Хорошо. Осталось только вписать значение и нажать на кнопку «Проверка решения». Система покажет, что произойдет дальше (как будет выглядеть заполнение полей). Если число подсвечивается оранжевым, что-то не так. Скорее всего, нужно искать другие значения, чтобы вписывать в ячейку.

What does the orange color of the two in square 3 mean? The game suggests that the number has no place here. Accordingly, 2 should be written in the only remaining cell - at the top right. The system helped to solve another question: now we know where 8 should be. Thanks to the tool, we managed not only to complete square 3, but also to understand how to fill the cells further.

Results

So, after completing square #3, there is still a puzzle left to complete.

Let's see what to do in square #8, where we should have placed 2 and 6. Now we can already see where to put the 2. We have a 2 in square #2 (left column). In order to avoid crossings, 2 should be placed in the right column of square #8. Accordingly, in the empty cell of square #8 we should write 6. It will look like 1-8-7-6-6-4-2-9-9-5-3.

The solution of Sudoku is so close! It remains only to fill in two cells located in square #2. Here we don't need any more dangling fruit or serious attempts to rotate the twists. We need to insert the values 8 and 6 (based on what we see in the corresponding columns).

You managed to solve sudoku quickly! The puzzle is complete, and now you can move on to other fields.

In the course of solving logic problems, you can often get stumped. That is, you can't tell which digit fits the square/column/cell better. In this case, you should use special online tools like "Solution Hints" or "Checks". Such techniques will be useful for both beginners and experts in solving puzzles.