c34026b101
note: done using ```sh git grep -l "2010-2024 Google" | xargs sed -i 's/2010-2024 Google/2010-2025 Google/' ```
82 lines
3.1 KiB
Protocol Buffer
82 lines
3.1 KiB
Protocol Buffer
// Copyright 2010-2025 Google LLC
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Protobuf representing a flow problem on a graph. It supports several problem
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// types. Depending on the type, the message is interpreted differently as
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// explained under each type description below.
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//
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// LINEAR_SUM_ASSIGNMENT: the algorithm computes the minimum-cost perfect
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// matching if there is one.
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// - Arcs are assumed to be from a left node to a right node. In particular
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// the id space of the left and right nodes can be the same. That is an arc
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// from the left node 0 to the right node 0 will be coded as (0, 0).
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// - If a perfect matching does not exist, the problem is not feasible.
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// - Capacity and supply values are ignored.
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//
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// MAX_FLOW: The algorithm computes the maximum flow under the arc capacity
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// constraints.
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// - Only one source (with supply > 0) and one sink (with supply < 0), the
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// supply values are not important. Only the signs are.
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// - The costs are ignored.
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//
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// MIN_COST_FLOW: the algorithm computes the flow of minimum cost. If a feasible
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// flow does not exist (in particular if the sum of supplies is not 0), the
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// problem is not feasible.
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syntax = "proto2";
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package operations_research;
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option java_package = "com.google.ortools.graph";
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option java_multiple_files = true;
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option csharp_namespace = "Google.OrTools.Graph";
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message FlowArcProto {
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// A directed arc goes from a tail node to a head node.
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// Node ids must be non-negative (>= 0).
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optional int64 tail = 1;
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optional int64 head = 2;
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// Capacity of the arc. Must be non-negative (>= 0). If the capacity is zero,
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// it is equivalent to not including the arc in the FlowModelProto.
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optional int64 capacity = 3 [default = 1];
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// Cost of this arc per unit of flow.
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// Note that it can take any positive, negative or null value.
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optional int64 unit_cost = 4 [default = 0];
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}
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message FlowNodeProto {
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// The ids must be non-negative (>= 0). They should be dense for good
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// performance. Note that it is not mandatory to include nodes with no supply
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// in a FlowModelProto.
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optional int64 id = 1;
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// The supply can be positive or negative in which case it means demand.
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// The sum of the supplies over all nodes must always be 0.
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optional int64 supply = 2 [default = 0];
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}
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// Holds a flow problem, see NodeProto and ArcProto for more details.
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message FlowModelProto {
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repeated FlowNodeProto nodes = 1;
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repeated FlowArcProto arcs = 2;
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// The type of problem to solve.
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enum ProblemType {
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LINEAR_SUM_ASSIGNMENT = 0;
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MAX_FLOW = 1;
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MIN_COST_FLOW = 2;
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}
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optional ProblemType problem_type = 3;
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}
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