
| Medium Puzzle #39 - 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 | 2 | 5 | 8 | Medium Puzzle #39 - November 8, 2005 | ||||||||
| 2 | 4 | 9 | 8 | 2 | 1 | Original puzzle as published © joe-ks.com | ||||||
| 3 | 7 | 1 | 4 | |||||||||
| 4 | 9 | 4 | 8 | |||||||||
| 5 | 3 | 7 | 4 | 6 | ||||||||
| 6 | 1 | 5 | 3 | 7 | ||||||||
| 7 | 1 | 3 | ||||||||||
| 8 | 6 | 8 | 9 | 4 | 7 | 2 | ||||||
| 9 | 2 | 9 | 5 | |||||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 5 | 8 | Step 1: Column G needs #1: #1 MUST go in Cell G5 | ||||||||
| 2 | 4 | 9 | 8 | 2 | 1 | (#1 in Row 3 @ E1 excludes use of Cell G3, & | ||||||
| 3 | 7 | 1 | 4 | #1 in Row 7 @ A7 excludes use of Cell G7) | ||||||||
| 4 | 9 | 4 | 8 | |||||||||
| 5 | 3 | 7 | 4 | 6 | 1 | |||||||
| 6 | 1 | 5 | 3 | 7 | ||||||||
| 7 | 1 | 3 | ||||||||||
| 8 | 6 | 8 | 9 | 4 | 7 | 2 | ||||||
| 9 | 2 | 9 | 5 | |||||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 5 | 8 | Step 2: #1 is now in Columns G & I: #1 MUST go in Cell H8... | ||||||||
| 2 | 4 | 9 | 8 | 2 | 1 | |||||||
| 3 | 7 | 1 | 4 | Step 3: #1 is now in Rows 7 & 8: #1 MUST go in Cell F9 | ||||||||
| 4 | 9 | 4 | 8 | (#1 in Column D @ D6 excludes use of Cell D9) | ||||||||
| 5 | 3 | 7 | 4 | 6 | 1 | |||||||
| 6 | 1 | 5 | 3 | 7 | ||||||||
| 7 | 1 | 3 | ||||||||||
| 8 | 6 | 8 | 9 | 4 | 7 | 1 | 2 | |||||
| 9 | 2 | 1 | 9 | 5 | ||||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 5 | 8 | Step 4: Block II needs # 8: #8 MUST go in Cell G7 | ||||||||
| 2 | 4 | 9 | 8 | 2 | 1 | (#8 in Column I @ I4 excludes use of Cells I7 & I9) | ||||||
| 3 | 7 | 1 | 4 | |||||||||
| 4 | 9 | 4 | 8 | Step 5: #8 is now in Rows 7 & 8: #8 MUST go in Cell D9... | ||||||||
| 5 | 3 | 7 | 4 | 6 | 1 | |||||||
| 6 | 1 | 5 | 3 | 7 | ||||||||
| 7 | 1 | 8 | 3 | |||||||||
| 8 | 6 | 8 | 9 | 4 | 7 | 1 | 2 | |||||
| 9 | 8 | 2 | 1 | 9 | 5 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 4 | 5 | 8 | Step 6: #4 is in Rows 2 & 3: #4 MUST go in Cell F1 | |||||||
| 2 | 4 | 9 | 8 | 2 | 1 | (#4 in Column D @ D5 excludes use of Cell D1, & | ||||||
| 3 | 7 | 1 | 4 | #4 in Column E @ E8 excludes use of Cell E1) | ||||||||
| 4 | 9 | 4 | 8 | |||||||||
| 5 | 3 | 7 | 4 | 6 | 1 | Step 7: #6 is in Row 8 (@ A8 in Block GG): #6 must go in | ||||||
| 6 | 1 | 5 | 3 | 7 | Blocks HH in either D7 or F7… BUT that means that #6 | |||||||
| 7 | 1 | 8 | 3 | in Block II MUST go in Block II, Row 9 - & it MUST be in | ||||||||
| 8 | 6 | 8 | 9 | 4 | 7 | 1 | 2 | the only cell remaining - in Cell I9) | ||||
| 9 | 8 | 2 | 1 | 9 | 5 | 6 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 7 | 4 | 5 | 8 | Step 8: Complete Block II: #4 MUST go in Cell I7... | ||||||
| 2 | 4 | 9 | 8 | 2 | 7 | 1 | ||||||
| 3 | 7 | 1 | 4 | Step 9: #7 is in Columns G & I: #7 MUST go in Cell H2… | ||||||||
| 4 | 9 | 4 | 8 | |||||||||
| 5 | 3 | 7 | 4 | 6 | 1 | Step 10: #7 is now in Rows 2 & 3: #7 MUST go in Cell C1 | ||||||
| 6 | 1 | 5 | 3 | 7 | (#7 in Column B @ B5 excludes use of Cell B1) | |||||||
| 7 | 1 | 8 | 3 | 4 | ||||||||
| 8 | 6 | 8 | 9 | 4 | 7 | 1 | 2 | |||||
| 9 | 8 | 2 | 1 | 9 | 5 | 6 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 7 | 4 | 5 | 8 | Step 11: Complete Column G: #6 MUST go in Cell G3... | ||||||
| 2 | 4 | 9 | 8 | 2 | 7 | 1 | ||||||
| 3 | 7 | 1 | 6 | 4 | Step 12: #7 is in Columns B & C: #7 MUST go in Cell A9... | |||||||
| 4 | 9 | 4 | 8 | |||||||||
| 5 | 3 | 7 | 4 | 6 | 1 | |||||||
| 6 | 1 | 5 | 3 | 7 | ||||||||
| 7 | 1 | 8 | 3 | 4 | ||||||||
| 8 | 6 | 8 | 9 | 4 | 7 | 1 | 2 | |||||
| 9 | 7 | 8 | 2 | 1 | 9 | 5 | 6 | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 7 | 4 | 5 | 8 | Step 13: Block HH needs #3: #3 MUST go in Cell F8 | ||||||
| 2 | 4 | 9 | 8 | 2 | 7 | 1 | (#3 in Row 7 @ H7 excludes use of Cells D7, E7 & F7) | |||||
| 3 | 7 | 1 | 6 | 4 | ||||||||
| 4 | 9 | 4 | 8 | Step 14: #5 is in Columns G & H: #5 MUSt go in Cell I5… | ||||||||
| 5 | 3 | 7 | 4 | 6 | 1 | 5 | ||||||
| 6 | 1 | 5 | 3 | 7 | ||||||||
| 7 | 1 | 8 | 3 | 4 | ||||||||
| 8 | 6 | 8 | 9 | 4 | 3 | 7 | 1 | 2 | ||||
| 9 | 7 | 8 | 2 | 1 | 9 | 5 | 6 | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 7 | 4 | 5 | 8 | Step 15: #9 is in Rows 8 & 9: #9 MUST go in Cell C7 | ||||||
| 2 | 4 | 9 | 8 | 2 | 7 | 1 | (#9 in Column B @ B2 excludes use of Cell B9) | |||||
| 3 | 7 | 1 | 6 | 4 | ||||||||
| 4 | 9 | 4 | 8 | |||||||||
| 5 | 3 | 7 | 4 | 6 | 1 | 5 | ||||||
| 6 | 1 | 5 | 3 | 7 | ||||||||
| 7 | 1 | 9 | 8 | 3 | 4 | |||||||
| 8 | 6 | 8 | 9 | 4 | 3 | 7 | 1 | 2 | ||||
| 9 | 7 | 8 | 2 | 1 | 9 | 5 | 6 | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 1 | 7 | 4 | 5 | 8 | Step 16: #1 is in Rows 2 & 3: #1 MUST go in Cell B1... | |||||
| 2 | 4 | 9 | 8 | 2 | 7 | 1 | ||||||
| 3 | 7 | 1 | 6 | 4 | Step 17: #1 is now in Columns A & B: #1 MUST go in Cell C4 | |||||||
| 4 | 9 | 1 | 4 | 8 | (#1 in Row 5 @ G5 excludes use of Cell C5, & | |||||||
| 5 | 3 | 7 | 4 | 6 | 1 | 5 | #1 in Row 6 @ D6 excludes use of Cell C6) | |||||
| 6 | 1 | 5 | 3 | 7 | ||||||||
| 7 | 1 | 9 | 8 | 3 | 4 | |||||||
| 8 | 6 | 8 | 9 | 4 | 3 | 7 | 1 | 2 | ||||
| 9 | 7 | 8 | 2 | 1 | 9 | 5 | 6 | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 1 | 7 | 6 | 4 | 5 | 8 | Step 18: Block AA needs #6: #6 MUST go in Cell C2 | ||||
| 2 | 4 | 9 | 6 | 8 | 2 | 7 | 1 | (#6 in row 3 @ G3 exludes use of Cells A3, B3 & C3) | ||||
| 3 | 7 | 1 | 6 | 4 | ||||||||
| 4 | 9 | 1 | 4 | 8 | Step 19: #6 is now in Rows 2 & 3: #6 MUST go in Cell D1 | |||||||
| 5 | 3 | 7 | 4 | 6 | 1 | 5 | (#6 in Column E @ E5 excludes use of Cell E1) | |||||
| 6 | 1 | 5 | 3 | 7 | ||||||||
| 7 | 1 | 9 | 6 | 8 | 3 | 4 | Step 20: #6 in now in Columns D & E: #6 MUST go in Cell F7 | |||||
| 8 | 6 | 8 | 9 | 4 | 3 | 7 | 1 | 2 | ||||
| 9 | 7 | 8 | 2 | 1 | 9 | 5 | 6 | |||||