Fewest knight moves across a chessboard
A knight sits on an 8 x 8 board and moves in the usual L-shape (two squares one way, one square perpendicular). Squares are (row, col) with 0 <= row, col < 8.
start = (0, 0), goal = (7, 7)
-> 6 # the corner-to-corner knight distance
Return the minimum number of moves to reach the goal, or -1 if impossible.
Your answer
This one is open-ended. Work it through, then check your reasoning against the full solution.