LP problem mask and QUBO Reformulation

solvers/cplex/mip/mip.py

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+import argparse
+import cplex
+import sys
+
+parser = argparse.ArgumentParser(
+    description="Solve a MIP problem from an MPS file using IBM CPLEX."
+)
+parser.add_argument("input_file", help="Path to the input MPS file.")
+parser.add_argument("output_file", help="Path to write the solution.")
+args = parser.parse_args()
+
+try:
+    cpx = cplex.Cplex()
+    cpx.read(args.input_file)
+except cplex.exceptions.CplexError as exc:
+    print("Error reading the MPS file:", exc)
+    sys.exit(1)
+
+
+try:
+    cpx.solve()
+except cplex.exceptions.CplexError as exc:
+    print("Error during solve:", exc)
+    sys.exit(1)
+
+status = cpx.solution.get_status()
+with open(args.output_file, 'w') as out_file:
+    out_file.write("Solution status: {}\n".format(cpx.solution.get_status_string()))
+    out_file.write("Objective value = {}\n".format(cpx.solution.get_objective_value()))
+    var_names = cpx.variables.get_names()
+    var_values = cpx.solution.get_values()
+    for name, val in zip(var_names, var_values):
+        out_file.write("{:<15} = {}\n".format(name, val))
+print("Solution written to", args.output_file)

solvers/cplex/mip/requirements.txt

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+cplex

solvers/gams/mip/LICENSE.txt

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+MIT License
+
+Copyright (c) 2024 GAMS Software GmbH <[email protected]>
+Copyright (c) 2024 GAMS Development Corp. <[email protected]>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

solvers/gams/mip/mip_to_qubo_reformulation.gms

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+$setEnv GAMSINP "%INPUT%"
+$setEnv GAMSPEN "%PENALTY%"
+
+$onEmbeddedCode Python:
+import os
+import sys
+import subprocess
+import re
+
+inp_file = os.environ.get('GAMSINP')
+print(f"{inp_file}")
+
+if not os.path.exists(inp_file):
+    sys.exit(f"*** ERROR: input file not found: {inp_file}")
+
+# Replace .lp or .mps with .gms
+base, ext = os.path.splitext(inp_file)
+new_name = base + '.gms'
+
+cmd = ['mps2gms', inp_file]
+print(f"--- Running: {' '.join(cmd)}")
+res = subprocess.run(
+    cmd,
+    stdout=subprocess.PIPE,
+    stderr=subprocess.PIPE
+)
+
+with open(new_name, 'r', encoding='utf-8', errors='ignore') as f:
+    content = f.read()
+
+pattern = re.compile(
+    r'Solve\s+(\S+)\s+using\s+(\S+)\s+(maximizing|minimizing)\s+(\S+)\s*;',
+    re.IGNORECASE
+)
+match = pattern.search(content)
+if not match:
+    sys.exit('*** ERROR: No "Solve ... using ..." statement found in generated .gms file')
+
+model_name  = match.group(1)  # e.g. "m"
+model_type  = match.group(2)  # e.g. "LP" or "MIP"
+sense_text  = match.group(3)  # "maximizing" or "minimizing"
+obj_var     = match.group(4)  # e.g. "x7"
+
+if sense_text.lower().startswith('max'):
+    gams_sense = 'max'
+else:
+    gams_sense = 'min'
+
+# Create the replacement line using the matched groups
+penalty = os.environ.get("GAMSPEN", "100")  # Default to 100 if not set
+new_line = f'$batinclude %IDIR% {model_name} {model_type} {gams_sense} {obj_var} {penalty} -logOn=2'
+
+# Replace the matching "Solve ..." line with the new line (only the first occurrence)
+new_content = pattern.sub(new_line, content, count=1)
+
+solution_block = r'''
+$setNames "%INPUT%" fp fn fe
+$if not set SOLOUTPUT $set SOLOUTPUT %fp%solution%fe%
+file solFile / "%SOLOUTPUT%" /;
+put solFile 'c Solution of %INPUT%';
+put solFile / 's m ';
+
+if((m.modelstat = %modelStat.Optimal% or m.modelstat = %modelStat.IntegerSolution%) or m.solvestat = %solveStat.NormalCompletion%,
+   put solFile / 'Optimal solution found.';
+   put solFile / 'Objective value: ' obj.l:0:0;
+   put solFile / 'Variable values:';
+   loop(j,
+       put solFile / j.tl:0 ' = ' xi.l(j):0:0;
+   );
+else
+   put solFile / 'Error: no solution was returned.';
+);
+'''
+
+# Append the solution parsing code at the end of the .gms file.
+new_content += "\n" + solution_block
+# Write the modified content back to the .gms file
+with open(new_name, 'w', encoding='utf-8', errors='ignore') as f:
+    f.write(new_content)
+$offEmbeddedCode