Enter line 1: Enter line 2: Enter line 3: Enter line 4: Enter line 5: Enter line 6: Enter line 7: Enter line 8: Enter line 9: 

Input puzzle:

000235000
009000701
004000206
010800040
750106093
060002070
301000500
807000900
000471000

Number of attempts: 0
Number of backtracks: 0

Solution:

176 | 235 | 489
239 | 684 | 751
584 | 719 | 236
---------------
913 | 857 | 642
752 | 146 | 893
468 | 392 | 175
---------------
341 | 928 | 567
827 | 563 | 914
695 | 471 | 328