Let's play the third Sudoku game at third level hardness
This is the third game play session at Sudoku third level. For many this may be quite a high level, but just like any other human activity area, if you are experienced it would seem easy to you. In this third game play at the third level while playing the game we needed to use three digit long cycle through frequent use of DSA. Once we can form such a cycle, things started getting easier.
As is the custom we will still use row-column scan, DSA will be the main technique along with cycles. To know what a cycle or DSA is you may refer to our first and second game play sessions at level 2.
Let us play the game.
The Sudoku third level game play session 3
First valid cells, R3C1 4, scan R1,R2,C2 -- R4C5 4, scan R5,R6,C4 -- R9C7 4, scan C8,C9,R8 -- R7C3 4, scan R8,R9,C2 4 over -- R5C3 5, scan C2,R6 -- R4C4 5, scan R5,R6 -- R9C6 5, scan R7,R8,C4 -- R3C5 5, scan C4,C6 -- R1C9 5, scan R2,R3,C7 5 over.
Then the next steps, R4C9 3, DSA [2,3,6] in R4 -- R5C5 6, DSA [3,6,9] in C5 -- Cycle (2,7) formed in R5, R5C7 1 -- R1C3 7, scan C2,R2 -- R3C7 7, scan R1,R2,C8 -- R7C4 1, scan C5,C6 as cycle (1,2) formed in R9 out of DSA [1,2,7,9] in R9 and simultaneously a second cycle (7,9) formed in R8C1 and R9C4. This latter cycle blocked R7C4 for 1 and provided the necessary breakthrough.
Notice that we are still refraining from writing a 4 digit DS in a cell, but writing practically all 3 digit DSs in the cells. We feel lucky if we get a 2 digit DS in a cell.
We know as the games are getting harder, nothing will come easy, we need to be patient and wait for a cycle or other useful structure to form out of writing the DSs.
The following is the result till now. Let us go over to the next stage that should not be difficult.
We start with a cycle and carry on merrily, Cycle (3,6,9) in C7 - R1C7, R2C7, R8C7; R4C7 2 -- R4C2 6 -- R8C3 6, scan C1,C2, R9 -- R7C6 6, scan R8,R9,C5 -- R6C8 6 -- R2C7 6, scan C8,C9,R1 -- R3C4 6, scan R1,R2,C6 6 over -- Cycle (1,2,9) formed in R2, R2C1 (1,2,9), R2C4(2.9), R2C9(1,9) -- R2C3 8.
Now it is all routine, R2C8 3 -- R1C7 9, DSA cancel -- R2C9 1, DSA cancel -- R3C8 8 -- R3C6 9, DSA cancel -- R3C2 1 -- R2C4 2, DSA cancel -- R2C1 9 -- R1C2 2 -- R1C4 3, DSA cancel -- R1C6 8 -- R6C6 3, DSA cancel -- R6C5 9, DSA cancel -- R7C5 3 -- R8C7 3 -- R7C8 2, DSA cancel -- R7C2 9, DSA cancel -- R7C9 7 -- R8C9 9 -- R9C8 1 -- R9C3 2, DSA cancel -- R6C3 1 -- R6C1 2 -- R9C1 7, DSA cancel -- R8C1 1 -- R8C2 8 -- R9C4 9.
And the last few cells, R5C4 7 -- R5C6 2 -- R8C6 7. Game solved. End.
The final result is shown below.
Till a point it has been hard game and after the breakthrough it was pretty easy. Nevertheless you should try to solve in an easier path.
As usual we leave you here with a new game to solve.
Fourth game at Third level of hardness