solver(0,2,9,2,0,0,0,7,7,
[
[7,7,7,7,7,7,7],
 [7,7,_,_,_,7,7],
[7,7,_,_,_,_,7],
 [7,_,_,_,_,_,7],
[7,7,_,_,_,_,7],
 [7,7,_,_,_,7,7],
[7,7,7,7,7,7,7]
]).

Expected output:
7 7 7 7 7 7 7 
7 7 1 2 2 7 7 
7 7 7 7 7 2 7 
7 2 3 1 7 2 7 
7 7 3 7 7 2 7 
7 7 2 2 2 7 7 
7 7 7 7 7 7 7 

Expected output, if one replaces some 7s with 8s and staggering rows/columns (your output should be provided in the format above):
8 8 8 8 8 8 8
 8 8 1 2 2 8 8 
8 8 7 7 7 2 8 
 8 2 3 1 7 2 8 
8 8 3 7 7 2 8 
 8 8 2 2 2 8 8
8 8 8 8 8 8 8


The following puzzle is purely for illustrative purpose; your program is not expected to be sufficiently powerful to solve it within a minute.
solver(0,2,10,10,4,0,0,9,9,
[
[7,7,7,7,7,7,7,7,7],
 [7,7,_,_,_,_,7,7,7],
[7,7,_,_,_,_,_,7,7],
 [7,_,_,_,_,_,_,7,7],
[7,_,_,_,_,_,_,_,7],
 [7,_,_,_,_,_,_,7,7],
[7,7,_,_,_,_,_,7,7],
 [7,7,_,_,_,_,7,7,7],
[7,7,7,7,7,7,7,7,7]
]).

Expected output:
7 7 7 7 7 7 7 7 7 
7 7 1 1 7 2 7 7 7 
7 7 7 7 7 3 3 7 7 
7 2 3 3 3 7 2 7 7 
7 2 7 4 7 2 7 2 7 
7 3 4 4 3 7 2 7 7 
7 7 3 7 4 7 2 7 7 
7 7 2 3 3 2 7 7 7 
7 7 7 7 7 7 7 7 7 

Expected output, if one replaces some 7s with 8s and staggering rows/columns (your output should be provided in the format above):
8 8 8 8 8 8 8 8 8
 8 8 1 1 7 2 8 8 8 
8 8 7 7 7 3 3 8 8 
 8 2 3 3 3 7 2 8 8 
8 2 7 4 7 2 7 2 8 
 8 3 4 4 3 7 2 8 8 
8 8 3 7 4 7 2 8 8
 8 8 2 3 3 2 8 8 8
8 8 8 8 8 8 8 8 8

Actual result (Rotate image solution counter-clockwise to line it up with found algorithm solution).