On an N ¡Á N chessboard with a non-negative number in each grid, Kaka starts his matrix travels
with SUM = 0. For each travel, Kaka moves one rook from the left-upper grid to the right-bottom
one, taking care that the rook moves only to the right or down. Kaka adds the number to SUM in
each grid the rook visited, and replaces it with zero. It is not difficult to know the maximum
SUM Kaka can obtain for his first travel. Now Kaka is wondering what is the maximum SUM he can
obtain after his Kth travel. Note the SUM is accumulative during the K travels.
The first line contains two integers N and K (1 ¡Ü N ¡Ü 50, 0 ¡Ü K ¡Ü 10) described above. The
following N lines represents the matrix. You can assume the numbers in the matrix are no more
The maximum SUM Kaka can obtain after his Kth travel.
1 2 3
0 2 1
1 4 2
POJ Monthly--2007.10.06, Huang, Jinsong