# ❌ WRONG - "OPTIMAL" never matches, silently fails
if problem.Status.name == "OPTIMAL":
    print(problem.ObjValue)  # Never runs!

# ✅ CORRECT - use PascalCase
if problem.Status.name in ["Optimal", "FeasibleFound"]:
    print(problem.ObjValue)

print(f"Actual status: '{problem.Status.name}'")
print(f"Matches 'Optimal': {problem.Status.name == 'Optimal'}")
print(f"Matches 'OPTIMAL': {problem.Status.name == 'OPTIMAL'}")

for var in problem.getVariables():
    print(f"{var.VariableName} = {var.Value}")
print(f"Objective: {problem.ObjValue}")

# Or with direct variable references
for var in [x, y, z]:
    print(f"{var.VariableName}: {var.getValue()}")

if problem.Status.name in ["PrimalInfeasible", "Infeasible"]:
    print("Problem has no feasible solution")
    # Review constraints for conflicts
    for c in problem.getConstraints():
        print(f"{c.ConstraintName}")

# Check how variable was defined
int_var = problem.addVariable(
    lb=0, ub=10,
    vtype=INTEGER,  # Must be INTEGER, not CONTINUOUS
    name="count"
)

# Also check if status is actually optimal
if problem.Status.name == "FeasibleFound":
    print("Warning: not fully optimal, may have fractional intermediate values")

if problem.Status.name in ["DualInfeasible", "Unbounded"]:
    print("Problem is unbounded - objective can improve infinitely")

from cuopt.linear_programming.problem import LinearExpression

# Instead of: expr = c1*v1 + c2*v2 + ... + cn*vn (many terms)
vars_list = [v1, v2, v3, ...]
coeffs_list = [c1, c2, c3, ...]
expr = LinearExpression(vars_list, coeffs_list, constant=0.0)
problem.setObjective(expr, sense=MINIMIZE)

print(f"Variables: {len(problem.getVariables())}")
print(f"Constraints: {len(problem.getConstraints())}")

settings = SolverSettings()
settings.set_parameter("log_to_console", 1)  # See progress
settings.set_parameter("time_limit", 60)      # Don't wait forever

# For MILP, accept good-enough solution
settings.set_parameter("mip_relative_gap", 0.05)  # 5% gap

problem.solve(settings)
print(f"Solve time: {problem.SolveTime:.2f} seconds")

□ Status checked with correct case (PascalCase)?
□ All variables have correct vtype (INTEGER vs CONTINUOUS)?
□ Constraint directions correct (<= vs >= vs ==)?
□ Objective sense correct (MINIMIZE vs MAXIMIZE)?
□ Variable bounds specified where needed?