{

int prevX = tailX [0];

int prevY = tailY [0];

int prev2X, prev2Y;

tailX[0] = x;

tailY[0] = y;

for(int i = 1;i < nTail ; i++) {

prev2X = tailX[i];

prev2Y = tailY[i];

tailX[i] = prevX;

tailY[i] = prevY;

prevX = prev2X;

prevY = prev2Y ;

}

switch (dir) {

case LEFT:

x--;

break;

case RIGHT:

x++;

break;

case UP:

y--;

break;

case DOWN:

y++;

break;

default:

break;

}