>>180
A(1,1) = 1
A(i,i) = 2   (2≦i≦n)
A(i,i+1) = -1,
A(j+1,j) = -1,
A(i,j) = 0,  (|i-j|≧2)

B(i,j) = n+1 - Max{i,j} = min{n+1-i, n+1-j}