MIP 求解示例

以下示例展示了如何构建数学优化问题 然后使用 MathOpt 进行远程求解，并使用 OR API 进行远程求解。要获取 API 密钥，请按以下步骤操作： 请先按照设置指南操作。MathOpt 是或工具的一部分提供 从 9.9 版开始。如需了解详情，请参阅安装指南。

# solve_math_opt_model_via_http.py

"""Example of solving a MathOpt model through the OR API.

The model is built using the Python API, and the corresponding proto is
serialized to JSON to make the HTTP request.
"""

from collections.abc import Sequence

from absl import app
from absl import flags

from ortools.math_opt.python import mathopt
from ortools.math_opt.python.ipc import remote_http_solve

_API_KEY = flags.DEFINE_string("api_key", None, "API key for the OR API")

def request_example() -> None:
  """Run example using MathOpt `remote_http_solve` function."""
  # Set up the API key.
  api_key = _API_KEY.value
  if not api_key:
    print(
        "API key is required. See"
        " https://developers.google.com/optimization/service/setup for"
        " instructions."
    )
    return

  # Build a MathOpt model
  model = mathopt.Model(name="my_model")
  x = model.add_binary_variable(name="x")
  y = model.add_variable(lb=0.0, ub=2.5, name="y")
  model.add_linear_constraint(x + y <= 1.5, name="c")
  model.maximize(2 * x + y)
  try:
    result, logs = remote_http_solve.remote_http_solve(
        model,
        mathopt.SolverType.GSCIP,
        mathopt.SolveParameters(enable_output=True),
        api_key=api_key,
    )
    print("Objective value: ", result.objective_value())
    print("x: ", result.variable_values(x))
    print("y: ", result.variable_values(y))
    print("\n".join(logs))
  except remote_http_solve.OptimizationServiceError as err:
    print(err)

def main(argv: Sequence[str]) -> None:
  del argv  # Unused.
  request_example()

if __name__ == "__main__":
  app.run(main)