
| Medium Puzzle #37 - One Possible Solution Approach… | |||||||||||
| NB: There is only one final solution to this Sudoku puzzle… | |||||||||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | |||||||||||
| 2 | AA | BB | CC | Reference to 3x3 Blocks AA, BB & CC | |||||||
| 3 | |||||||||||
| 4 | |||||||||||
| 5 | DD | EE | FF | Reference to 3x3 Blocks DD, EE & FF | |||||||
| 6 | |||||||||||
| 7 | |||||||||||
| 8 | GG | HH | II | Reference to 3x3 Blocks GG, HH & II | |||||||
| 9 | |||||||||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 6 | Medium Puzzle #37 - November 6, 2005 | ||||||||
| 2 | 6 | 4 | 3 | 2 | 8 | Original puzzle as published © joe-ks.com | |||||
| 3 | 2 | 3 | 6 | 7 | |||||||
| 4 | 8 | 7 | 4 | ||||||||
| 5 | 4 | 9 | 3 | 6 | 5 | 7 | 8 | 1 | 2 | ||
| 6 | 5 | 2 | 3 | ||||||||
| 7 | 3 | 8 | 4 | 9 | |||||||
| 8 | 9 | 6 | 1 | 7 | 4 | ||||||
| 9 | 2 | 3 | |||||||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 6 | 3 | Step 1: #4 is in Columns A & C: #4 MUST go in Cell B9 | |||||||
| 2 | 6 | 4 | 3 | 2 | 8 | (#4 in Row 8 @ I9 excludes use of Cell B8) | |||||
| 3 | 2 | 3 | 6 | 7 | |||||||
| 4 | 8 | 7 | 4 | ||||||||
| 5 | 4 | 9 | 3 | 6 | 5 | 7 | 8 | 1 | 2 | Step 2: #3 is in Columns G & H: #3 MUST go in Cell I1... | |
| 6 | 5 | 2 | 3 | ||||||||
| 7 | 3 | 8 | 4 | 9 | |||||||
| 8 | 9 | 6 | 1 | 7 | 4 | ||||||
| 9 | 4 | 2 | 3 | ||||||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 6 | 3 | Step 3: #4 is in Rows 1 & 2: #4 MUST go in Cell H3 | |||||||
| 2 | 6 | 4 | 3 | 2 | 8 | (#4 in Column G @ G4 excludes use of Cell G3) | |||||
| 3 | 2 | 3 | 6 | 4 | 7 | ||||||
| 4 | 8 | 7 | 4 | ||||||||
| 5 | 4 | 9 | 3 | 6 | 5 | 7 | 8 | 1 | 2 | ||
| 6 | 5 | 2 | 3 | ||||||||
| 7 | 3 | 8 | 4 | 9 | |||||||
| 8 | 9 | 6 | 1 | 7 | 4 | ||||||
| 9 | 4 | 2 | 3 | ||||||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 6 | 3 | Step 4: #7 is in Column G & I: #7 MUST go in Cell H6 | |||||||
| 2 | 6 | 4 | 3 | 2 | 8 | (#7 in Row 4 @ C4 exlcudes use of Cell H4) | |||||
| 3 | 2 | 3 | 6 | 4 | 7 | ||||||
| 4 | 8 | 7 | 4 | Step 5: Block GG needs #2: #2 MUST go in Cell B8 | |||||||
| 5 | 4 | 9 | 3 | 6 | 5 | 7 | 8 | 1 | 2 | (#2 in Column C @ C6 excludes use of Cells C7 & C9, & | |
| 6 | 5 | 2 | 3 | 7 | #2 in Row 9 @ D9 further exludes use of Cell A9) | ||||||
| 7 | 3 | 8 | 4 | 2 | 9 | ||||||
| 8 | 9 | 2 | 6 | 1 | 7 | 4 | Step 6: #2 is now in Rows 8 & 9: #2 MUST go in Cell H7 | ||||
| 9 | 4 | 2 | 3 | (#2 in Column G @ G2 excludes use of Cell G7) | |||||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 6 | 3 | Step 7: #4 is in Columns D & F: #4 MUST go in Cell E6 | |||||||
| 2 | 6 | 4 | 3 | 2 | 8 | ||||||
| 3 | 2 | 3 | 6 | 4 | 7 | ||||||
| 4 | 8 | 7 | 4 | Step 8: #8 is in Columns G & I: #8 MUST go in Cell H8... | |||||||
| 5 | 4 | 9 | 3 | 6 | 5 | 7 | 8 | 1 | 2 | (#4 in Row 4 @ G4 excludes use of Cell E4) | |
| 6 | 5 | 2 | 4 | 3 | 7 | ||||||
| 7 | 3 | 8 | 4 | 2 | 9 | ||||||
| 8 | 9 | 2 | 6 | 1 | 7 | 8 | 4 | ||||
| 9 | 4 | 2 | 3 | ||||||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 1 | 4 | 6 | 3 | Step 9: Block GG needs #7: #8 MUST go in Cell A9 | ||||||
| 2 | 6 | 4 | 3 | 2 | 8 | (#7 in Column C @ C4 excludes use of Cells C7 & C9) | |||||
| 3 | 2 | 3 | 6 | 1 | 4 | 7 | |||||
| 4 | 8 | 7 | 4 | Step 10: Complete Column A: #1 MUST go in Cell A1... | |||||||
| 5 | 4 | 9 | 3 | 6 | 5 | 7 | 8 | 1 | 2 | ||
| 6 | 5 | 2 | 4 | 3 | 7 | Step 11: Block CC needs #1: #1 MUST go in Cell G3 | |||||
| 7 | 3 | 8 | 4 | 2 | 9 | (#1 from Step 10 @ A1 excludes use of Cell G1, & | |||||
| 8 | 9 | 2 | 6 | 1 | 7 | 8 | 4 | (#1 in Column H @ H5 excludes use of Cell H2) | |||
| 9 | 7 | 4 | 2 | 3 | |||||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 1 | 4 | 9 | 6 | 3 | Step 12: Clock FF needs #9: #9 MUST go in Cell H4 | |||||
| 2 | 6 | 4 | 3 | 2 | 8 | (#9 in Column I @ I7 excludes use of Cells I4 & I6) | |||||
| 3 | 2 | 3 | 6 | 1 | 4 | 7 | |||||
| 4 | 8 | 7 | 4 | 9 | Step 13: #9 is now in Columns H & I: #9 MUST go in Cell G1 | ||||||
| 5 | 4 | 9 | 3 | 6 | 5 | 7 | 8 | 1 | 2 | ||
| 6 | 5 | 2 | 4 | 3 | 7 | ||||||
| 7 | 3 | 8 | 4 | 2 | 9 | ||||||
| 8 | 9 | 2 | 6 | 1 | 7 | 8 | 4 | ||||
| 9 | 7 | 4 | 2 | 3 | |||||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 1 | 4 | 9 | 6 | 3 | Step 14: Complete Block CC: #5 MUST go in Cell H2... | |||||
| 2 | 6 | 4 | 3 | 2 | 5 | 8 | |||||
| 3 | 2 | 3 | 6 | 1 | 4 | 7 | Step 15: Complete Block FF: need #s 5 & 6… | ||||
| 4 | 8 | 6 | 7 | 4 | 9 | 5 | #5 can't go in Cell I6 (cf #5 in Row 6 @ A6), so | ||||
| 5 | 4 | 9 | 3 | 6 | 5 | 7 | 8 | 1 | 2 | #5 MUST go in Cell I4, & therefore #6 MUST go in Cell I6 | |
| 6 | 5 | 2 | 4 | 3 | 7 | 6 | |||||
| 7 | 3 | 8 | 4 | 2 | 9 | Step 16: #6 is now in Rows 5 & 6: #6 MUST go in Cell B4... | |||||
| 8 | 9 | 2 | 6 | 1 | 7 | 8 | 4 | ||||
| 9 | 7 | 4 | 2 | 3 | |||||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 1 | 4 | 9 | 6 | 3 | Step 17: Complete Block DD: #1 MUST go in Cell B6... | |||||
| 2 | 6 | 4 | 3 | 2 | 5 | 8 | |||||
| 3 | 2 | 3 | 6 | 1 | 4 | 7 | Step 18: #1 is in Columns G & H: #1 MUST go in Cell I9... | ||||
| 4 | 8 | 6 | 7 | 4 | 9 | 5 | |||||
| 5 | 4 | 9 | 3 | 6 | 5 | 7 | 8 | 1 | 2 | Step 19: #1 is now in Rows 8 & 9: #1 MUST go in Cell C7... | |
| 6 | 5 | 1 | 2 | 4 | 3 | 7 | 6 | ||||
| 7 | 3 | 8 | 1 | 4 | 2 | 9 | Step 20: Complete Block GG; #5 MUST go in Cell C9... | ||||
| 8 | 9 | 2 | 6 | 1 | 7 | 8 | 4 | ||||
| 9 | 7 | 4 | 5 | 2 | 3 | 1 | |||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 1 | 4 | 9 | 6 | 3 | Step 21: Complete Block II: Need #s 5 & 6… | |||||
| 2 | 6 | 4 | 3 | 2 | 5 | 8 | #5 can't go in Cell G9 (cf #5 from Step 20 in Row 9 @ C9) | ||||
| 3 | 2 | 3 | 6 | 1 | 4 | 7 | so #5 MUST go in Cell G7, & therefore #6 MUST go in G9 | ||||
| 4 | 8 | 6 | 7 | 4 | 9 | 5 | |||||
| 5 | 4 | 9 | 3 | 6 | 5 | 7 | 8 | 1 | 2 | Step 22: #6 is now in Rows 8 & 9: #6 MUST go in Cell E7 | |
| 6 | 5 | 1 | 2 | 4 | 3 | 7 | 6 | (#6 in Column D @ D5 excludes use of Cell D7) | |||
| 7 | 3 | 8 | 1 | 7 | 6 | 4 | 5 | 2 | 9 | ||
| 8 | 9 | 2 | 6 | 1 | 7 | 8 | 4 | Step 23: #7 is in Rows 8 & 9: #7 MUST go in Cell D7... | |||
| 9 | 7 | 4 | 5 | 2 | 6 | 3 | 1 | ||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 1 | 5 | |||||||||