func ordered(db *db.DB, a *assignment.Assignment) (l *cnf.Lit) {
// find the first in-order unassigned literal
for i := uint(1); i <= a.Len(); i++ {
if p, _ := a.Get(i); p == guess.Unassigned {
return &cnf.Lit{i, cnf.Pos}
}
}
return &cnf.Lit{0, 0}
}
func random(db *db.DB, a *assignment.Assignment) (l *cnf.Lit) {
sign := byte((rand.Int() % 2) + 1)
val := uint((rand.Int() % int(a.Len())) + 1)
for i := val; i <= a.Len(); i++ {
if v, _ := a.Get(i); v == guess.Unassigned {
return &cnf.Lit{i, sign}
}
}
for i := uint(1); i < val; i++ {
if v, _ := a.Get(i); v == guess.Unassigned {
return &cnf.Lit{i, sign}
}
}
return &cnf.Lit{0, 0}
}
func (lc *LitCounts) GetNextVmtf(a *assignment.Assignment) (l *cnf.Lit) {
var lit uint
for i := range lc.vmtf {
if lc.vmtf[i].lit < 0 {
lit = uint(-1 * lc.vmtf[i].lit)
} else {
lit = uint(lc.vmtf[i].lit)
}
if val, err := a.Get(lit); val == guess.Unassigned && err == nil {
if lc.vmtf[i].lit < 0 {
return &cnf.Lit{uint(lc.vmtf[i].lit * -1), cnf.Pos}
} else {
return &cnf.Lit{uint(lc.vmtf[i].lit), cnf.Pos}
}
}
}
panic("getNextVmtf is broken")
}