Bulldoku Level 431: Walkthrough & Solution
Step-by-step Bulldoku level 431 guide (7×7). One pup per color, row and column, no touching. Difficulty 45.0.
Play Level 431Step-by-step logic
1. Step: mark X in row 4
The yellow region is confined to row 4. Mark X on cells in that row that belong to other regions.
Board after step 1 2. Step: mark X in row 4
The yellow region is confined to row 4. Mark X on cells in that row that belong to other regions.
Board after step 2 3. Step: mark X in row 4
The yellow region is confined to row 4. Mark X on cells in that row that belong to other regions.
Board after step 3 4. Step: mark X in row 4
The yellow region is confined to row 4. Mark X on cells in that row that belong to other regions.
Board after step 4 5. Step: mark X in column 7
The mint region is confined to column 7. Mark illegal cells with X.
Board after step 5 6. Step: mark X in column 7
The mint region is confined to column 7. Mark illegal cells with X.
Board after step 6 7. Step: mark X in column 7
The mint region is confined to column 7. Mark illegal cells with X.
Board after step 7 8. Step: mark X in column 7
The mint region is confined to column 7. Mark illegal cells with X.
Board after step 8 9. Step: mark X in column 7
The mint region is confined to column 7. Mark illegal cells with X.
Board after step 9 10. Step: mark X in row 4
The yellow region is confined to row 4. Mark X on cells in that row that belong to other regions.
Board after step 10 11. Step: place pup (row 3, column 7)
After crosses, the mint region has only one legal cell — row 3, column 7. Place a pup there. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 11 12. Step: mark X (line reservation)
Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.
Board after step 12 13. Step: mark X in column 3
The orange region is confined to column 3. Mark illegal cells with X.
Board after step 13 14. Step: mark X in column 3
The orange region is confined to column 3. Mark illegal cells with X.
Board after step 14 15. Step: mark X (line reservation)
Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.
Board after step 15 16. Step: mark X (line reservation)
Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.
Board after step 16 17. Step: place pup (row 5, column 3)
After previous pups, column 3 has only one free cell — row 5. Place the orange region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 17 18. Step: place pup (row 4, column 1)
After previous pups, row 4 has only one free cell — column 1. Place the yellow region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 18 19. Step: place pup (row 2, column 2)
After crosses, the pink region has only one legal cell — row 2, column 2. Place a pup there. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 19 20. Step: logical elimination
Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.
Board after step 20 21. Step: logical elimination
Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.
Board after step 21 22. Step: place pup (row 6, column 6)
After previous pups, row 6 has only one free cell — column 6. Place the lavender region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 22 23. Step: place pup (row 1, column 5)
After previous pups, column 5 has only one free cell — row 1. Place the cyan region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 23 24. Step: place pup (row 7, column 4)
After previous pups, column 4 has only one free cell — row 7. Place the green region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 24
Final solution
All pups placed correctly: R1 C5, R2 C2, R3 C7, R4 C1, R5 C3, R6 C6, R7 C4
Similar difficulty levels
FAQ
- How do I solve Bulldoku level 431?
- Follow the 24 steps above: find forced placements first, then mark impossible cells with X.
- Where can I play level 431 online?
- Click "Play Level 431" to open the free browser game with this exact board.