Updated FindGUROBI.cmake to work with newer GUROBI versions

cmake/modules/FindGUROBI.cmake

@@ -1,20 +1,121 @@
-set(GUROBI_ROOT_DIR "" CACHE PATH "GUROBI root directory.")
+# - Find Gurobi Optimizer
+#
+# This module finds an installed Gurobi Optimizer library.
+# It is an independent implementation that is not based on the script
+# provided by Gurobi GmbH.
+#
+# USAGE:
+#   In your CMakeLists.txt, add the following:
+#   1. list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake") # Path to this file
+#   2. find_package(GUROBI REQUIRED)
+#   3. target_link_libraries(your_target PRIVATE Gurobi::gurobi)
+#
+# This module will define the following IMPORTED target:
+#   Gurobi::gurobi  - An interface library that links to Gurobi's C and C++
+#                     libraries and includes its headers.
+#
+# It also defines these variables, though using the target is preferred:
+#   GUROBI_FOUND          - True if Gurobi was found.
+#   GUROBI_INCLUDE_DIRS   - The Gurobi include directories.
+#   GUROBI_LIBRARIES      - A list of the Gurobi C and C++ libraries.
+#
+# The search for Gurobi is controlled by the following variables:
+#   GUROBI_HOME           - An environment variable pointing to the Gurobi
+#                           installation root (e.g., /opt/gurobi1003/linux64).
+#   GUROBI_ROOT_DIR       - A CMake variable that can be set to the Gurobi
+#                           installation root. Overrides GUROBI_HOME.
 
-STRING(REGEX MATCH "^[0-9]+" GUROBI_VERSION "${GUROBI_ROOT_DIR}")
+# Step 1: Find the Gurobi Root Directory
+# --------------------------------------------------------------------
+if(DEFINED ENV{GUROBI_HOME})
+    set(GUROBI_ROOT_DIR "$ENV{GUROBI_HOME}")
+endif()
 
-find_path(GUROBI_INCLUDE_DIR gurobi_c++.h HINTS "${GUROBI_ROOT_DIR}/include")
-find_library(GUROBI_LIBRARY libgurobi70.so HINTS ${GUROBI_ROOT_DIR}/lib)
-find_library(GUROBI_CPP_LIBRARY libgurobi_c++.a HINTS ${GUROBI_ROOT_DIR}/lib)
+# Allow the user to override the environment variable with a CMake variable
+set(GUROBI_ROOT_DIR "${GUROBI_ROOT_DIR}" CACHE PATH "Gurobi installation root directory")
 
+if(NOT EXISTS "${GUROBI_ROOT_DIR}")
+    message(FATAL_ERROR "Gurobi root directory not found. Please set GUROBI_HOME in your environment or GUROBI_ROOT_DIR in your CMake configuration.")
+endif()
+
+
+# Step 2: Extract the Gurobi Version from the Path
+# --------------------------------------------------------------------
+# This regex looks for "gurobi" followed by a sequence of digits (e.g., 1003)
+# in the path and captures the digits.
+string(REGEX MATCH "gurobi([0-9]+)" _ "${GUROBI_ROOT_DIR}")
+if(NOT CMAKE_MATCH_1)
+    message(WARNING "Could not determine Gurobi version from path: ${GUROBI_ROOT_DIR}. Assuming version 90 for library search.")
+    set(GUROBI_VERSION "90") # Fallback to a common older version
+else()
+    set(GUROBI_VERSION "${CMAKE_MATCH_1}")
+    # Gurobi library names don't use the patch number, e.g. 10.0.3 -> 100
+    string(SUBSTRING "${GUROBI_VERSION}" 0 3 GUROBI_VERSION_MAJOR_MINOR)
+    set(GUROBI_VERSION ${GUROBI_VERSION_MAJOR_MINOR})
+endif()
+
+
+# Step 3: Find the Required Components (Include directory and Libraries)
+# --------------------------------------------------------------------
+find_path(GUROBI_INCLUDE_DIR
+    NAMES gurobi_c++.h
+    HINTS "${GUROBI_ROOT_DIR}/include"
+    DOC "Path to the Gurobi C++ header file"
+)
+
+find_library(GUROBI_LIBRARY
+    NAMES gurobi${GUROBI_VERSION} # e.g., searches for libgurobi100.so
+    HINTS "${GUROBI_ROOT_DIR}/lib"
+    DOC "Gurobi C library"
+)
+
+find_library(GUROBI_CPP_LIBRARY
+    NAMES gurobi_c++
+    HINTS "${GUROBI_ROOT_DIR}/lib"
+    DOC "Gurobi C++ library"
+)
+
+
+# Step 4: Handle standard arguments and report result
+# --------------------------------------------------------------------
 include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(GUROBI DEFAULT_MSG GUROBI_LIBRARY GUROBI_CPP_LIBRARY GUROBI_INCLUDE_DIR)
+find_package_handle_standard_args(GUROBI
+    FOUND_VAR GUROBI_FOUND
+    REQUIRED_VARS GUROBI_LIBRARY GUROBI_CPP_LIBRARY GUROBI_INCLUDE_DIR
+    VERSION_VAR GUROBI_VERSION
+)
 
+
+# Step 5: Create Imported Target and set variables if found
+# --------------------------------------------------------------------
 if(GUROBI_FOUND)
-    set(GUROBI_INCLUDE_DIRS ${GUROBI_INCLUDE_DIR})
-    set(GUROBI_LIBRARIES ${GUROBI_CPP_LIBRARY} ${GUROBI_LIBRARY})
-    if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-        set(GUROBI_LIBRARIES "${GUROBI_LIBRARIES};m;pthread")
-    endif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-endif(GUROBI_FOUND)
-
-mark_as_advanced(GUROBI_LIBRARY GUROBI_CPP_LIBRARY GUROBI_INCLUDE_DIR)
+    # --- Create the modern IMPORTED target ---
+    if(NOT TARGET Gurobi::gurobi)
+        add_library(Gurobi::gurobi INTERFACE IMPORTED)
+        set_property(TARGET Gurobi::gurobi PROPERTY
+            INTERFACE_INCLUDE_DIRECTORIES "${GUROBI_INCLUDE_DIR}")
+
+        # Set system-specific libraries
+        set(GUROBI_SYSTEM_LIBS "")
+        if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+            set(GUROBI_SYSTEM_LIBS m pthread)
+        endif()
+
+        set_property(TARGET Gurobi::gurobi PROPERTY
+            INTERFACE_LINK_LIBRARIES "${GUROBI_CPP_LIBRARY};${GUROBI_LIBRARY};${GUROBI_SYSTEM_LIBS}")
+    endif()
+
+    # --- Set classic variables for compatibility ---
+    set(GUROBI_INCLUDE_DIRS "${GUROBI_INCLUDE_DIR}")
+    set(GUROBI_LIBRARIES "${GUROBI_CPP_LIBRARY}" "${GUROBI_LIBRARY}")
+
+    if(NOT GUROBI_FIND_QUIETLY)
+      message(STATUS "Found Gurobi: ${GUROBI_ROOT_DIR} (version ${GUROBI_VERSION})")
+      message(STATUS "  - Gurobi C++ Library: ${GUROBI_CPP_LIBRARY}")
+      message(STATUS "  - Gurobi C Library: ${GUROBI_LIBRARY}")
+    endif()
+
+endif()
+
+# Mark internal variables as advanced so they don't show up in the default CMake GUI
+mark_as_advanced(GUROBI_ROOT_DIR GUROBI_INCLUDE_DIR GUROBI_LIBRARY GUROBI_CPP_LIBRARY)

include/andres/graph/minimum-spanning-tree.hxx

@@ -5,6 +5,7 @@
 #include <queue>
 #include <stdexcept>
 #include <vector>
+#include <limits>
 
 #include "andres/functional.hxx"
 #include "subgraph.hxx"

include/andres/graph/multicut-lifted/greedy-additive.hxx

@@ -8,6 +8,7 @@
 #include <algorithm>
 #include <map>
 #include <queue>
+#include <limits>
 
 #include "andres/partition.hxx"
 

include/andres/graph/multicut-lifted/kernighan-lin.hxx

@@ -8,6 +8,7 @@
 #include <set>
 #include <vector>
 #include <stack>
+#include <limits>
 
 
 

include/andres/graph/multicut/kernighan-lin.hxx

@@ -7,6 +7,7 @@
 #include <stdexcept>
 #include <set>
 #include <vector>
+#include <limits>
 
 #include "../complete-graph.hxx"
 

include/andres/graph/multicut/preprocessing.hxx

@@ -3,6 +3,7 @@
 #define ANDRES_GRAPH_MULTICUT_PREPROCESSING_HXX
 
 #include <cmath>
+#include <limits>
 
 #include "andres/graph/components.hxx"
 #include "andres/graph/bridges.hxx"
@@ -15,7 +16,8 @@ namespace multicut {
 // Edge contraction operation by masking
 // First vertex of given node pair stays in the graph, the other one is removed (masked)
 // Flags affected vertices in optional flag pointer
-void contract(andres::graph::Graph<> & graph, std::vector<double> & edge_costs, 
+template <typename T>
+void contract(andres::graph::Graph<T> & graph, std::vector<double> & edge_costs, 
     std::vector<char> & emask, std::vector<char> & vmask, std::vector<size_t> pair,
     std::vector<std::pair<std::pair<size_t,size_t>, char>> & constr, std::vector<char> * flag = NULL)
 {