The question of the Tangshan nine-square grid competition was wrong

The solution of the nine-square grid competition is analyzed item by item

　　The nine-square grid, also known as beginner sudoku, is a simplified version of the Sudoku game that is perfect for beginners to get started. Its rules are very simple: in a 9x9 grid, place a chain of numbers 1-8. Find the corresponding question on many Sudoku game websites, just follow the steps below to easily solve it.

Step 1: Observe first: the observation house, that is, the 3x3 grid. Observe if only one row of houses has numbers to easily find candidate numbers. For example, if there are only the numbers 3 and 6 in the middle of the house, if the other numbers in the other two rows of a palace are already complete, and there is a 6 in the next row, there must be 3 in this row.

Step 2: Speculate: Using known information to speculate on unknown numbers is an effective strategy. For example, a common number A appears frequently in two rows of a certain palace, and A also appears in the other house and the conflict area.

Step 3: Positioning: For difficult questions, combine the tools of "Horizontal + 3" to display the sum and "Vertical + 4" to display the sum to assist in generating candidate numbers. This feature increases completion to 90% by just a few more isolated numbers.

Tips to share: Make good use of the residual exclusion method. If only one A is needed in a house (e.g., a house with only one vacancy), the entire candidate number can be listed, arranged with other houses, and the same number can be excluded to further reduce the feasibility.

　　Try our site's practice questions for free to improve your skills! Through the continuous exercise and analysis of the questions, feel the process of getting started for the first time and going deep into it! Use the [Hidden Benefits] on the website to receive exclusive topics and guides! Continue to search for the secrets of cracking logic and experience the joy and sense of accomplishment of solving the nine-square grid! The transition from novice to veteran only requires trial and persistence step by step. I wish you success in your challenge!