Given a chessboard target coordinate, return the minimum number of knight moves needed to reach it from the origin. Pattern focus: Unweighted BFS distance. The knight move graph is unweighted, so BFS gives the shortest number of moves.
x = target column, y = target row on an infinite chessboard
minimum number of knight moves from (0,0) to (x,y)
Example 1:
Input:
x = 2 y = 1
Output:
1
Explanation:
A knight can reach (2,1) in one move.
Example 2:
Input:
x = 5 y = 5
Output:
4
Explanation:
BFS finds the minimum number of knight moves.
Example 3:
Input:
x = 0 y = 0
Output:
0
Explanation:
The origin is already the target.