Forked from Zhouxing-Su/Lemon.MinCostFlow.NS.Sample.cpp
Created
November 11, 2020 02:36
-
-
Save evilying/73a2cf16224f9b8af9fdc87cd0659297 to your computer and use it in GitHub Desktop.
Sample code of using Network Simplex in Lemon for Min Cost Flow problem.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#include <iostream> | |
#include <lemon/smart_graph.h> | |
#include <lemon/network_simplex.h> | |
using namespace lemon; | |
using namespace std; | |
using Weight = int; | |
using Capacity = int; | |
using Graph = SmartDigraph; | |
using Node = Graph::Node; | |
using Arc = Graph::Arc; | |
template<typename ValueType> | |
using ArcMap = SmartDigraph::ArcMap<ValueType>; | |
using NS = NetworkSimplex<SmartDigraph, Capacity, Weight>; | |
int main() { | |
Graph g; | |
Node u = g.addNode(); | |
Node v = g.addNode(); | |
Arc a = g.addArc(u, v); | |
Arc b = g.addArc(u, v); | |
ArcMap<Weight> weights(g); | |
weights[a] = 5; | |
weights[b] = 2; | |
ArcMap<Capacity> capacities(g); | |
capacities[a] = 10; | |
capacities[b] = 5; | |
NS ns(g); | |
ns.costMap(weights).upperMap(capacities).stSupply(u, v, 12); | |
ArcMap<Capacity> flows(g); | |
NS::ProblemType status = ns.run(); | |
switch (status) { | |
case NS::INFEASIBLE: | |
cerr << "insufficient flow" << endl; | |
break; | |
case NS::OPTIMAL: | |
ns.flowMap(flows); | |
cerr << "flow[a]=" << ns.flow(a) << " flow[b]=" << flows[b] << endl; | |
cerr << "cost=" << ns.totalCost() << endl; | |
break; | |
case NS::UNBOUNDED: | |
cerr << "infinite flow" << endl; | |
break; | |
default: | |
break; | |
} | |
return 0; | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment