Refactoring d'un composant logiciel (3/3)

public ISolver makeQueens(int n) {
    ISolver solver = new Solver();
    var queens = new Variable[n];
    // diagonals
    var diagonals1 = new Variable[n];
    var diagonals2 = new Variable[n];
    for (int i = 0; i < n; i++) {
        queens[i] = solver.newVar("R" + i, 1, n);
        diagonals1[i] = solver.expression(queens[i], "+", i);
        diagonals2[i] = solver.expression(queens[i], "-", i);
    }
    solver.addAllDiffRelation(queens);
    solver.addAllDiffRelation(diagonals1);
    solver.addAllDiffRelation(diagonals2);
    solver.alwaysReduceStrategy();
    solver.setVerbose(false);
    return solver;
}

public ISolver buildAssignmentProblem(int[][] costs) {
    var solver = new Solver();
    int nbTasks = costs.length;
    int nbAgents = costs[0].length;
    Variable[][] matrix = new Variable[nbTasks][nbAgents];
    
    // create nbTasks * nbAgents variables 0..1
    for (int t = 0; t < nbTasks; t++) {
        for (int a = 0; a < nbAgents; a++) {
            matrix[t][a] = solver.newVar("T" + t + "A" + a, 0, 1);
        }
    }
    
    // each task have one agent
    var zero = solver.newConstant(0);
    for (int t = 0; t < nbTasks; t++) {
        var sum = zero;
        for (int a = 0; a < nbAgents; a++) {
            sum = solver.expression(sum, "+", matrix[t][a]);
        }
        solver.addRelation(sum, "=", 1);
    }
    
    // each agent have at most one task
    for (int a = 0; a < nbAgents; a++) {
        var sum = zero;
        for (int t = 0; t < nbTasks; t++) {
            sum = solver.expression(sum, "+", matrix[t][a]);
        }
        solver.addRelation(sum, "<=", 1);
    }
    
    // compute cost
    var cost = zero;
    for (int t = 0; t < nbTasks; t++) {
        for (int a = 0; a < nbAgents; a++) {
            cost = solver.expression(cost, "+", matrix[t][a], "*", costs[t][a]);
        }
    }
    var varCost = solver.newVar("cost");
    solver.addRelation(cost, "=", varCost);
    solver.setVerbose(false);
        solver.alwaysReduceStrategy();
    // Code a adapter pour minimiser cost
    ....
    ....
    return solver;
}