( x1 , y1 ) and ( x2 , y2 ) are two positions . these can be different according to situation . From position of knight , the chess board can be divided into four blocks i . e . . N - E , E - S , S - W , W - N .
if ( x <= tx ) { if ( y <= ty ) { x1 = x + 2 ; y1 = y + 1 ; x2 = x + 1 ; y2 = y + 2 ; } else { x1 = x + 2 ; y1 = y - 1 ; x2 = x + 1 ; y2 = y - 2 ; } } else { if ( y <= ty ) { x1 = x - 2 ; y1 = y + 1 ; x2 = x - 1 ; y2 = y + 2 ; } else { x1 = x - 2 ; y1 = y - 1 ; x2 = x - 1 ; y2 = y - 2 ; } }