Changeset 1264:92ba3e62825d in lemon-0.x for src/work/athos/lp/lp_test.cc

Timestamp:

03/25/05 19:56:07 (20 years ago)

Author:

Alpar Juttner

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@1691

Message:

Constraints (expressions containing <= or >=) can be passed to addRow()
and setRow()

File:

• src/work/athos/lp/lp_test.cc (modified) (3 diffs)

src/work/athos/lp/lp_test.cc

@@ -1 +1 @@
 #include"lp_solver_skeleton.h"
 #include"lp_glpk.h"
+#include<lemon/list_graph.h>
 
 using namespace lemon;
@@ -37 +38 @@
   lp.addRow(LP::INF,3.0*(p1+p2*2-5*p3+12-p4/3)+2*p4-4,23);
   lp.addRow(LP::INF,3.0*(x[1]+x[2]*2-5*x[3]+12-x[4]/3)+2*x[4]-4,23);
+
+  lp.addRow(x[1]+x[3]<=x[5]-3);
+  lp.addRow(-7<=x[1]+x[3]-12<=3);
 }
 
+
+template<class G,class C>
+double maxFlow(const G &g,const C &cap,typename G::Node s,typename G::Node t)
+{
+  LpGlpk lp;
+  
+  typedef G Graph;
+  typedef typename G::Node Node;
+  typedef typename G::NodeIt NodeIt;
+  typedef typename G::Edge Edge;
+  typedef typename G::EdgeIt EdgeIt;
+  typedef typename G::OutEdgeIt OutEdgeIt;
+  typedef typename G::InEdgeIt InEdgeIt;
+  
+  typename G::EdgeMap<LpGlpk::Col> x(g);
+  // lp.addColSet(x);
+  for(EdgeIt e(g);e!=INVALID;++e) x[e]=lp.addCol();
+  
+  for(EdgeIt e(g);e!=INVALID;++e) {
+    lp.setColUpperBound(x[e],cap[e]);
+    lp.setColLowerBound(x[e],0);
+  }
+
+  for(NodeIt n(g);n!=INVALID;++n) if(n!=s&&n!=t) {
+    LpGlpk::Expr ex;
+    for(InEdgeIt  e(g,n);e!=INVALID;++e) ex+=x[e];
+    for(OutEdgeIt e(g,n);e!=INVALID;++e) ex-=x[e];
+    lp.addRow(0,ex,0);
+  }
+  {
+    LpGlpk::Expr ex;
+    for(InEdgeIt  e(g,t);e!=INVALID;++e) ex+=x[e];
+    for(OutEdgeIt e(g,t);e!=INVALID;++e) ex-=x[e];
+    lp.setObj(ex);
+  }
+
+  lp.solve();
+
+  return 0;
+}
 
 int main() 
@@ -47 +91 @@
   lpTest(lp_skel);
   lpTest(lp_glpk);
+
+  ListGraph g;
+  ListGraph::EdgeMap<double> cap(g);
+  
+  maxFlow(g,cap,ListGraph::NodeIt(g),ListGraph::NodeIt(g));
+
 }