or-tools NewIntVar seems not supporting int64 in python

问题

Dears, I'm trying to create NewIntVar with lower bound an higher bound equal to the one of the int64:

(-9.223.372.036.854.775.808 to +9.223.372.036.854.775.807)

But I get the Model invalid error when I try to solve the model. The max range I found as working (trying manually) is the following model.NewIntVar(-93.372.036.854.775.808, 9.123.372.036.854.775.807,'pippo')

Do you know why int64 is not supported?

Thanks Stefano

回答1:

From the source code I see:

https://github.com/google/or-tools/blob/stable/ortools/sat/cp_model_checker.cc#L90

  const int64 ub = proto.domain(proto.domain_size() - 1);
  if (lb < kint64min + 2 || ub > kint64max - 1) {
    return absl::StrCat(
        "var #", v, " domain do not fall in [kint64min + 2, kint64max - 1]. ",
        ProtobufShortDebugString(proto));
  }

  // We do compute ub - lb in some place in the code and do not want to deal
  // with overflow everywhere. This seems like a reasonable precondition anyway.
  if (lb < 0 && lb + kint64max < ub) {
    return absl::StrCat(
        "var #", v,
        " has a domain that is too large, i.e. |UB - LB| overflow an int64: ",
        ProtobufShortDebugString(proto));
  }

So the values actually are:

cp_model.INT_MIN + 2 (-9223372036854775806)
cp_model.INT_MAX - 1 (9223372036854775806)

And max-min can't exceed kint64max (9223372036854775807)

You could use INT32_MAX and INT32_MIN instead or a range that satisfies these conditions.

来源：https://stackoverflow.com/questions/61272596/or-tools-newintvar-seems-not-supporting-int64-in-python

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