satSolver_old.h

/**************************************************************************************************
MiniSat -- Copyright (c) 2005, Niklas Sorensson
http://www.cs.chalmers.se/Cs/Research/FormalMethods/MiniSat/

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
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NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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**************************************************************************************************/
// Modified to compile with MS Visual Studio 6.0 by Alan Mishchenko

#ifndef satSolver_h
#define satSolver_h


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include "satVec.h"
#include "satMem.h"

ABC_NAMESPACE_HEADER_START

//#define USE_FLOAT_ACTIVITY

//=================================================================================================
// Public interface:

struct sat_solver_t;
typedef struct sat_solver_t sat_solver;

extern sat_solver* sat_solver_new(void);
extern void        sat_solver_delete(sat_solver* s);

extern int         sat_solver_addclause(sat_solver* s, lit* begin, lit* end);
extern int         sat_solver_simplify(sat_solver* s);
extern int         sat_solver_solve(sat_solver* s, lit* begin, lit* end, ABC_INT64_T nConfLimit, ABC_INT64_T nInsLimit, ABC_INT64_T nConfLimitGlobal, ABC_INT64_T nInsLimitGlobal);
extern void        sat_solver_rollback( sat_solver* s );

extern int         sat_solver_nvars(sat_solver* s);
extern int         sat_solver_nclauses(sat_solver* s);
extern int         sat_solver_nconflicts(sat_solver* s);

extern void        sat_solver_setnvars(sat_solver* s,int n);

extern void        Sat_SolverWriteDimacs( sat_solver * p, char * pFileName, lit* assumptionsBegin, lit* assumptionsEnd, int incrementVars );
extern void        Sat_SolverPrintStats( FILE * pFile, sat_solver * p );
extern int *       Sat_SolverGetModel( sat_solver * p, int * pVars, int nVars );
extern void        Sat_SolverDoubleClauses( sat_solver * p, int iVar );

// trace recording
extern void        Sat_SolverTraceStart( sat_solver * pSat, char * pName );
extern void        Sat_SolverTraceStop( sat_solver * pSat );
extern void        Sat_SolverTraceWrite( sat_solver * pSat, int * pBeg, int * pEnd, int fRoot );

// clause storage
extern void        sat_solver_store_alloc( sat_solver * s );
extern void        sat_solver_store_write( sat_solver * s, char * pFileName );
extern void        sat_solver_store_free( sat_solver * s );
extern void        sat_solver_store_mark_roots( sat_solver * s );
extern void        sat_solver_store_mark_clauses_a( sat_solver * s );
extern void *      sat_solver_store_release( sat_solver * s ); 

//=================================================================================================
// Solver representation:

struct clause_t;
typedef struct clause_t clause;

struct sat_solver_t
{
    int      size;          // nof variables
    int      cap;           // size of varmaps
    int      qhead;         // Head index of queue.
    int      qtail;         // Tail index of queue.

    // clauses
    vecp     clauses;       // List of problem constraints. (contains: clause*)
    vecp     learnts;       // List of learnt clauses. (contains: clause*)

    // activities
#ifdef USE_FLOAT_ACTIVITY
    double   var_inc;       // Amount to bump next variable with.
    double   var_decay;     // INVERSE decay factor for variable activity: stores 1/decay. 
    float    cla_inc;       // Amount to bump next clause with.
    float    cla_decay;     // INVERSE decay factor for clause activity: stores 1/decay.
    double*  activity;      // A heuristic measurement of the activity of a variable.
#else
    int      var_inc;       // Amount to bump next variable with.
    int      cla_inc;       // Amount to bump next clause with.
    unsigned*activity;      // A heuristic measurement of the activity of a variable.
#endif

    vecp*    wlists;        // 
    lbool*   assigns;       // Current values of variables.
    int*     orderpos;      // Index in variable order.
    clause** reasons;       //
    int*     levels;        //
    lit*     trail;
    char*    polarity;

    clause*  binary;        // A temporary binary clause
    lbool*   tags;          //
    veci     tagged;        // (contains: var)
    veci     stack;         // (contains: var)

    veci     order;         // Variable order. (heap) (contains: var)
    veci     trail_lim;     // Separator indices for different decision levels in 'trail'. (contains: int)
    veci     model;         // If problem is solved, this vector contains the model (contains: lbool).
    veci     conf_final;    // If problem is unsatisfiable (possibly under assumptions),
                            // this vector represent the final conflict clause expressed in the assumptions.

    int      root_level;    // Level of first proper decision.
    int      simpdb_assigns;// Number of top-level assignments at last 'simplifyDB()'.
    int      simpdb_props;  // Number of propagations before next 'simplifyDB()'.
    double   random_seed;
    double   progress_estimate;
    int      verbosity;     // Verbosity level. 0=silent, 1=some progress report, 2=everything

    stats_t    stats;

    ABC_INT64_T   nConfLimit;    // external limit on the number of conflicts
    ABC_INT64_T   nInsLimit;     // external limit on the number of implications
    int           nRuntimeLimit; // external limit on runtime

    veci     act_vars;      // variables whose activity has changed
    double*  factors;       // the activity factors
    int      nRestarts;     // the number of local restarts
    int      nCalls;        // the number of local restarts
    int      nCalls2;        // the number of local restarts
 
    Sat_MmStep_t * pMem;

    int      fSkipSimplify; // set to one to skip simplification of the clause database
    int      fNotUseRandom; // do not allow random decisions with a fixed probability

    int *    pGlobalVars;   // for experiments with global vars during interpolation
    // clause store
    void *   pStore;
    int      fSolved;

    // trace recording
    FILE *   pFile;
    int      nClauses;
    int      nRoots;

    veci     temp_clause;    // temporary storage for a CNF clause
};

static int sat_solver_var_value( sat_solver* s, int v ) 
{
    assert( s->model.ptr != NULL && v < s->size );
    return (int)(s->model.ptr[v] == l_True);
}
static int sat_solver_var_literal( sat_solver* s, int v ) 
{
    assert( s->model.ptr != NULL && v < s->size );
    return toLitCond( v, s->model.ptr[v] != l_True );
}
static void sat_solver_act_var_clear(sat_solver* s) 
{
    int i;
    for (i = 0; i < s->size; i++)
        s->activity[i] = 0.0;
    s->var_inc = 1.0;
}
static void sat_solver_compress(sat_solver* s) 
{
    if ( s->qtail != s->qhead )
    {
        int RetValue = sat_solver_simplify(s);
        assert( RetValue != 0 );
    }
}

static int sat_solver_final(sat_solver* s, int ** ppArray)
{
    *ppArray = s->conf_final.ptr;
    return s->conf_final.size;
}

static int sat_solver_set_runtime_limit(sat_solver* s, int Limit)
{
    int nRuntimeLimit = s->nRuntimeLimit;
    s->nRuntimeLimit = Limit;
    return nRuntimeLimit;
}

static int sat_solver_set_random(sat_solver* s, int fNotUseRandom)
{
    int fNotUseRandomOld = s->fNotUseRandom;
    s->fNotUseRandom = fNotUseRandom;
    return fNotUseRandomOld;
}

ABC_NAMESPACE_HEADER_END

#endif