/// <summary>
/// Represents linear programming problem(1. target function, 2. constraint system, 3. zero constraints)
/// </summary>
/// <param name="targetFunction"></param>
/// <param name="constraints">Constraint system with zero constraints</param>
/// <exception cref="FormatException"></exception>
/// <exception cref="NullReferenceException"></exception>
public LinearProgrammingProblem(TargetFunction targetFunction, ICollection<Constraint> constraints)
{
if (!IsLinearFormula(targetFunction.Formula))
throw new FormatException("Target function must be linear");
TargetFunction = new TargetFunction(targetFunction);
SetConstraintSystem(constraints);
CompleteTargetFunction();
}
/// <summary>
/// Represents linear programming problem(1. target function, 2. constraint system, 3. zero constraints)
/// </summary>
/// <param name="targetFunction"></param>
/// <param name="constraints">Constraint system without zero constraints</param>
/// <param name="zeroConstraints">Zero constraints</param>
/// <exception cref="FormatException"></exception>
/// <exception cref="NullReferenceException"></exception>
public LinearProgrammingProblem(TargetFunction targetFunction, IEnumerable<Constraint> constraints,
IEnumerable<Constraint> zeroConstraints)
: this(targetFunction, CombineConstraints(constraints, zeroConstraints))
{
}
/// <summary>
/// Parses target function
/// </summary>
/// <param name="problemDescription">LPP or just target function description</param>
public static TargetFunction ParseTargetFunction(IList<string> problemDescription)
{
var flag = false;
var formula = new List<Variable>();
var target = string.Empty;
var mLabels = new List<string>();
for (var i = 0; i < problemDescription.Count; i++)
{
if (problemDescription[i].Replace(" ", "") == "->")
{
target = problemDescription[i + 1].Replace(" ", "");
break;
}
if (flag)
{
if (problemDescription[i].Contains("M"))
{
mLabels.Add(problemDescription[i].Substring(problemDescription[i].IndexOf("M", StringComparison.Ordinal) + 1));
continue;
}
try
{
formula.Add(CreateVariable(problemDescription[i]));
}
catch (FormatException)
{
return null;
}
}
if (problemDescription[i].Replace(" ", "") == "f(x)=")
flag = true;
}
var tf = new TargetFunction(formula, target);
foreach (var label in mLabels)
tf.AddVariableWithMaxCoefficient(label);
return tf;
}
/// <summary>
/// Compares two target functions
/// </summary>
public static bool IsTargetFunctionsEquals(TargetFunction first, TargetFunction second)
{
if (first.Target != second.Target || first.Arguments.Count != second.Arguments.Count)
return false;
foreach (var varF in first.Formula)
{
var flag = false;
foreach (var varS in second.Formula)
{
if (varF.Label != varS.Label) continue;
if (varF.Coefficient != varS.Coefficient || varF.Power != varS.Power)
return false;
flag = true;
break;
}
if (flag == false)
return false;
}
return true;
}
/// <summary>
/// Represents copy of target function
/// </summary>
/// <exception cref="NullReferenceException"></exception>
/// <exception cref="FormatException"></exception>
public TargetFunction(TargetFunction targetFunction)
: this(targetFunction._formula, targetFunction.Target)
{
_variablesWithMaxCoefficient = new List<string>(targetFunction._variablesWithMaxCoefficient);
}
/// <summary>
/// Represents discrete programming problem description
/// (1. target function, 2. constraint system, 3. zero constraints, 4. whole constraint)
/// </summary>
/// <param name="targetFunction">Target function</param>
/// <param name="constraints">Constraint system without zero constraints</param>
/// <param name="zeroConstraints">Zero constraints</param>
/// <param name="wholeConstraints">Variables with whole constraint</param>
public DiscreteProgrammingProblem(TargetFunction targetFunction, IEnumerable<Constraint> constraints,
IEnumerable<Constraint> zeroConstraints, IEnumerable<string> wholeConstraints)
: base(targetFunction, constraints, zeroConstraints)
{
WholeConstraints = new List<string>(wholeConstraints);
}
/// <summary>
/// Represents discrete programming problem description
/// (1. target function, 2. constraint system, 3. zero constraints, 4. whole constraint)
/// </summary>
/// <param name="targetFunction">Target function</param>
/// <param name="constraintSystem">Constraint system with zero constraints</param>
/// <param name="wholeConstraints">Variables with whole constraint</param>
public DiscreteProgrammingProblem(TargetFunction targetFunction, ICollection<Constraint> constraintSystem,
IEnumerable<string> wholeConstraints)
: base(targetFunction, constraintSystem)
{
WholeConstraints = new List<string>(wholeConstraints);
}