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knapsack

<table align="left"> <td> <a href="https://colab.research.google.com/github/google/or-tools/blob/main/examples/notebook/algorithms/knapsack.ipynb">Run in Google Colab</a> </td> <td> <a href="https://github.com/google/or-tools/blob/main/ortools/algorithms/samples/knapsack.py">View source on GitHub</a> </td> </table>

First, you must install ortools package in this colab.

python

%pip install ortools

A simple knapsack problem.

python

from ortools.algorithms.python import knapsack_solver



def main():
    # Create the solver.
    solver = knapsack_solver.KnapsackSolver(
        knapsack_solver.SolverType.KNAPSACK_MULTIDIMENSION_BRANCH_AND_BOUND_SOLVER,
        "KnapsackExample",
    )

    values = [
        # fmt:off
      360, 83, 59, 130, 431, 67, 230, 52, 93, 125, 670, 892, 600, 38, 48, 147,
      78, 256, 63, 17, 120, 164, 432, 35, 92, 110, 22, 42, 50, 323, 514, 28,
      87, 73, 78, 15, 26, 78, 210, 36, 85, 189, 274, 43, 33, 10, 19, 389, 276,
      312
        # fmt:on
    ]
    weights = [
        # fmt: off
      [7, 0, 30, 22, 80, 94, 11, 81, 70, 64, 59, 18, 0, 36, 3, 8, 15, 42, 9, 0,
       42, 47, 52, 32, 26, 48, 55, 6, 29, 84, 2, 4, 18, 56, 7, 29, 93, 44, 71,
       3, 86, 66, 31, 65, 0, 79, 20, 65, 52, 13],
        # fmt: on
    ]
    capacities = [850]

    solver.init(values, weights, capacities)
    computed_value = solver.solve()

    packed_items = []
    packed_weights = []
    total_weight = 0
    print("Total value =", computed_value)
    for i in range(len(values)):
        if solver.best_solution_contains(i):
            packed_items.append(i)
            packed_weights.append(weights[0][i])
            total_weight += weights[0][i]
    print("Total weight:", total_weight)
    print("Packed items:", packed_items)
    print("Packed_weights:", packed_weights)


main()