Implemented TU test via Eulerian submatrices.

doc/changes.md

@@ -1,5 +1,6 @@
 # Change Log # {#changes}
 
+  - Revised the matroid decomposition structure.
   - Fixed a bug in the code for printing dot-files for transposed graphic/network matrices; reported by Christopher Hojny.
   - Added a `timeLimit` parameter to all potentially time intensive functions.
   - Bugfix for the `timeLimit` parameter.

doc/tu.md

@@ -17,11 +17,13 @@ determines whether the matrix given in file `IN-MAT` is totally unimodular.
   - `-i FORMAT`  Format of file `IN-MAT`, among `dense` for \ref dense-matrix and `sparse` for \ref sparse-matrix; default: dense.
   - `-D OUT-DEC` Write a decomposition tree of the underlying regular matroid to file `OUT-DEC`; default: skip computation.
   - `-N NON-SUB` Write a minimal non-totally-unimodular submatrix to file `NON-SUB`; default: skip computation.
-  - `-s`         Print statistics about the computation to stderr.
 
 **Advanced options:**
+  - `--stats`              Print statistics about the computation to stderr.
+  - `--time-limit LIMIT`   Allow at most LIMIT seconds for the computation.
   - `--no-direct-graphic`  Check only 3-connected matrices for regularity.
   - `--no-series-parallel` Do not allow series-parallel operations in decomposition tree.
+  - `--algo ALGO`          Use algorithm from {decomposition, submatrix, partition}; default: decomposition.
 
 If `IN-MAT` is `-` then the matrix is read from stdin.
 If `OUT-DEC` or `NON-SUB` is `-` then the decomposition tree (resp. the submatrix) is written to stdout.
@@ -54,6 +56,8 @@ In order to repeat experiments described in the paper above, the function can be
 
 The corresponding function in the library is
 
-  - CMRtestTotalUnimodularity() tests a matrix for being totally unimodular.
+  - CMRtuTest() tests a matrix for being totally unimodular.
 
 and is defined in \ref tu.h.
+Its parameters also allow to choose one of the enumeration algorithms with exponential running time instead of the decomposition algorithm.
+

include/cmr/tu.h

@@ -21,7 +21,7 @@ extern "C" {
 typedef enum
 {
   CMR_TU_ALGORITHM_DECOMPOSITION = 0, /**< \brief Algorithm based on Seymour's decomposition of regular matroids. */
-  CMR_TU_ALGORITHM_SUBMATRIX = 1,     /**< \brief Enumeration algorithm based on submatrices. */
+  CMR_TU_ALGORITHM_EULERIAN = 1,      /**< \brief Enumeration algorithm based on Eulerian submatrices. */
   CMR_TU_ALGORITHM_PARTITION = 2      /**< \brief Enumeration algorithm based on criterion of Ghouila-Houri. */
 } CMR_TU_ALGORITHM;
 
@@ -47,7 +47,19 @@ CMR_ERROR CMRtuParamsInit(
  * \brief Statistics for recognition algorithm for [totally unimodular](\ref tu) matrices.
  */
 
-typedef CMR_REGULAR_STATS CMR_TU_STATS;
+typedef struct
+{
+  CMR_REGULAR_STATS decomposition;    /**< Statistics for regular matroid decomposition algorithm. */
+
+  uint32_t enumerationRowSubsets;     /**< Number of considered row subsets in enumeration algorithm. */
+  uint32_t enumerationColumnSubsets;  /**< Number of considered column subsets in enumeration algorithm. */
+  double enumerationTime;             /**< Total time of enumeration algorithm. */
+
+  uint32_t partitionRowSubsets;       /**< Number of considered row subsets in partition algorithm. */
+  uint32_t partitionColumnSubsets;    /**< Number of considered column subsets in partition algorithm. */
+  double partitionTime;               /**< Total time of partition algorithm. */
+
+} CMR_TU_STATS;
 
 /**
  * \brief Initializes all statistics for recognition algorithm for [totally unimodular](\ref tu) matrices.