Rank and Diagonal (or vice versa Diagonal and Rank): . . .…
Rank and Diagonal (or vice versa Diagonal and Rank):
. . . . . . / .
. . . . . b . .
. . . . / . . .
. . . / . . . .
. . / . . . . .
. / . . . . . .
s-----a--------
. . . . . . . .
> diagonalIndex := rankIndex - fileIndex;