Just execute:
sudoku-solver <your-grid>
<your-grid> is 81 figures, 0 being an empty cell, the first figure being the top-left most cell,
the last being the bottom-right most cell.
Examples of grid :
000000000040800950080206000008090120000304000036080500000402030017009040000000000 diabolic
100007090030020008009600500005300900010080002600004000300000010040000007007000300 "AI Escargot"
000050000800900000700120300003002004680010000042000080000004002007000043005070600 diabolic
070400030000000059500601000080950000000030000000200800006000300809020047000700006 difficult
580003000920004100000008350709020008002000700300050201046700000005900072000300046 medium
006700409507091060094080070250009600900057380008316002602000500700960000040008030 easy
This solver works without bruteforcing, just plain logic.