IVec<BigInteger> coefficients = new Vec<BigInteger>(colors);
for (int k = 1; k <= colors; k++) {
literals.push(numberOfVertices * colors + k);
coefficients.push(BigInteger.ONE);
}
ObjectiveFunction objFunc = new ObjectiveFunction(literals,
coefficients);
solver.setObjectiveFunction(objFunc);
/* Solve */
IOptimizationProblem op = (IOptimizationProblem) solver;