Solving Constraint Integer Programs

Interface changes between SCIP 1.1 and SCIP 1.2

New and changed callbacks

  • The callback SCIP_DECL_PRICERREDCOST(x) in the pricers has two new parameters:
    • A result pointer determines whether the pricer guarantees that there exist no more variables. This allows for early branching.
    • A pointer for providing a lower bound.

New parameters in interface methods

  • SCIPcalcMIR() in scip.h has two new parameter "mksetcoefsvalid" and "sol". The parameter "mksetcoefsvalid" stores whether the coefficients of the mixed knapsack set ("mksetcoefs") computed in SCIPlpCalcMIR() are valid. If the mixed knapsack constraint obtained after aggregating LP rows is empty or contains too many nonzero elements the generation of the c-MIR cut is aborted in SCIPlpCalcMIR() and "mksetcoefs" is not valid. The input parameter "sol" can be used to separate a solution different from the LP solution.


  • A significant change for C++ users is that all include files of SCIP automatically detect C++ mode, i.e., no extern "C" is needed anymore.

For further release notes we refer to the Release notes.