for (int i=0; i<nodes.size(); i++) {
for (int j=0; j<numTiles; j++) {  double[] con = lp.getEmptyConstraint(); con[pNum(0,j)] = 1; lp.addConstraintEQ(con, 0);  con = lp.getEmptyConstraint(); con[pNum(nodes.size()-1,j)] = 1; lp.addConstraintEQ(con, 0); }  for (int i=1; i<nodes.size()-1; i++) {
    private void constrainOneTilePerNode(LinearProgram lp) {	for (int i=0; i<nodes.size(); i++) {	     double[] con = lp.getEmptyConstraint();	     for (int j=0; j<numTiles; j++) {		 con[pNum(i,j)] = 1;	     }	     lp.addConstraintEQ(con, 1);	}    }