<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><P>Hello nicolas:</P>
<P> Fortunately,it is a mixed 0-1 integer programming problem,and successfully solved by CPLEX.</P>
<P> The result is as follows: </P>
<P>Welcome to IBM(R) ILOG(R) CPLEX(R) Interactive Optimizer 12.6.3.0<BR> with Simplex, Mixed Integer & Barrier Optimizers<BR>5725-A06 5725-A29 5724-Y48 5724-Y49 5724-Y54 5724-Y55 5655-Y21<BR>Copyright IBM Corp. 1988, 2015. All Rights Reserved.</P>
<P>Type 'help' for a list of available commands.<BR>Type 'help' followed by a command name for more<BR>information on commands.</P>
<P>CPLEX> read bug.mps<BR>Selected objective sense: MINIMIZE<BR>Selected objective name: C<BR>Selected RHS name: RHS1<BR>Selected range name: RNG1<BR>Selected bound name: BND1<BR>Problem 'bug.mps' read.<BR>Read time = 0.16 sec. (0.79 ticks)<BR>CPLEX> optimize<BR>Tried aggregator 5 times.<BR>MIP Presolve eliminated 1629 rows and 1354 columns.<BR>MIP Presolve modified 1110 coefficients.<BR>Aggregator did 268 substitutions.<BR>Reduced MIP has 307 rows, 276 columns, and 919 nonzeros.<BR>Reduced MIP has 119 binaries, 0 generals, 0 SOSs, and 0 indicators.<BR>Presolve time = 0.06 sec. (4.38 ticks)<BR>Found incumbent of value 1.0991956e+018 after 0.17 sec. (4.97 ticks)<BR>Probing fixed 13 vars, tightened 21 bounds.<BR>Probing time = 0.00 sec. (0.09 ticks)<BR>Tried aggregator 2 times.<BR>MIP Presolve eliminated 103 rows and 101 columns.<BR>MIP Presolve modified 79 coefficients.<BR>Aggregator did 6 substitutions.<BR>Reduced MIP has 197 rows, 169 columns, and 578 nonzeros.<BR>Reduced MIP has 67 binaries, 0 generals, 0 SOSs, and 0 indicators.<BR>Presolve time = 0.00 sec. (0.60 ticks)<BR>Probing fixed 0 vars, tightened 1 bounds.<BR>Probing time = 0.00 sec. (0.05 ticks)<BR>Tried aggregator 1 time.<BR>MIP Presolve eliminated 10 rows and 12 columns.<BR>MIP Presolve modified 13 coefficients.<BR>Reduced MIP has 187 rows, 157 columns, and 554 nonzeros.<BR>Reduced MIP has 63 binaries, 0 generals, 0 SOSs, and 0 indicators.<BR>Presolve time = 0.00 sec. (0.32 ticks)<BR>Probing time = 0.00 sec. (0.04 ticks)<BR>Clique table members: 14.<BR>MIP emphasis: balance optimality and feasibility.<BR>MIP search method: dynamic search.<BR>Parallel mode: deterministic, using up to 4 threads.<BR>Root relaxation solution time = 0.00 sec. (0.39 ticks)</P>
<P> Nodes Cuts/<BR> Node Left Objective IInf Best Integer Best Bound ItCnt Gap</P>
<P>* 0+ 0 1.09920e+018 8.18653e+017 25.52%<BR>* 0+ 0 8.50858e+017 8.18653e+017 3.78%<BR> 0 0 8.22495e+017 4 8.50858e+017 8.22495e+017 8 3.33%<BR>* 0+ 0 8.25697e+017 8.22495e+017 0.39%<BR> 0 0 8.22495e+017 5 8.25697e+017 Cuts: 16 20 0.39%<BR>* 0+ 0 8.22495e+017 8.22495e+017 0.00%<BR> 0 0 cutoff 8.22495e+017 8.22495e+017 20 0.00%<BR>Elapsed time = 0.23 sec. (11.98 ticks, tree = 0.00 MB, solutions = 3)</P>
<P>Clique cuts applied: 3<BR>Implied bound cuts applied: 5<BR>Mixed integer rounding cuts applied: 2<BR>Gomory fractional cuts applied: 4</P>
<P>Root node processing (before b&c):<BR> Real time = 0.25 sec. (12.05 ticks)<BR>Parallel b&c, 4 threads:<BR> Real time = 0.00 sec. (0.00 ticks)<BR> Sync time (average) = 0.00 sec.<BR> Wait time (average) = 0.00 sec.<BR> ------------<BR>Total (root+branch&cut) = 0.25 sec. (12.05 ticks)</P>
<P>Solution pool: 4 solutions saved.</P>
<P>MIP - Integer optimal solution: Objective = 8.2249485120e+017<BR>Solution time = 0.61 sec. Iterations = 20 Nodes = 0<BR>Deterministic time = 12.06 ticks (19.83 ticks/sec)</P>
<P> But the global optimization solvers,such as SCIP,BARON,COUENNE,can't bring the same result as CPLEX.</P>
<P> Does it mean that Soplex is inferior to CPLEX,which serves as the default linear programming solver in SCIP?</P>
<P> </P>
<P> </P>
<P> Best Wishes,</P>
<P> From Wei. </P><br><br><br><hr size="1"><br><div><a href="http://score.mail.sohu.com/?ref=mail_tailad"><img border="0" src="http://ad.mail.sohu.com/mail/images/score_ad_foot1_750x79.png" /> </a></div>
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