--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Implab/Automaton/DFATable.cs	Thu Mar 03 08:41:02 2016 +0300
@@ -0,0 +1,280 @@
+using Implab;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Implab.Automaton {
+    public class DFATable : IDFATableBuilder {
+        DFAStateDescriptior[] m_dfaTable;
+
+        int m_stateCount;
+        int m_symbolCount;
+        int m_initialState;
+
+        readonly HashSet<int> m_finalStates = new HashSet<int>();
+        readonly HashSet<AutomatonTransition> m_transitions = new HashSet<AutomatonTransition>();
+
+        void AssertNotReadOnly() {
+            if (m_dfaTable != null)
+                throw new InvalidOperationException("The object is readonly");
+        }
+
+
+        #region IDFADefinition implementation
+
+        public DFAStateDescriptior[] GetTransitionTable() {
+            if (m_dfaTable == null) {
+                if (m_stateCount <= 0)
+                    throw new InvalidOperationException("Invalid automaton definition: states count = {0}", m_stateCount);
+                if (m_symbolCount <= 0)
+                    throw new InvalidOperationException("Invalid automaton definition: symbols count = {0}", m_symbolCount);
+
+                m_dfaTable = ConstructTransitionTable();
+            }
+            return m_dfaTable;
+        }
+
+        public bool IsFinalState(int s) {
+            Safe.ArgumentInRange(s, 0, m_stateCount, "s");
+
+            return m_dfaTable != null ? m_dfaTable[s].final :  m_finalStates.Contains(s);
+        }
+
+        public IEnumerable<int> FinalStates {
+            get {
+                return m_finalStates;
+            }
+        }
+
+        public int StateCount {
+            get { return m_stateCount; }
+        }
+
+        public int AlphabetSize {
+            get { return m_symbolCount; }
+        }
+
+        public int InitialState {
+            get { return m_initialState; }
+        }
+
+        #endregion
+
+        protected virtual DFAStateDescriptior[] ConstructTransitionTable() {
+            var dfaTable = new DFAStateDescriptior[m_stateCount];
+
+
+            foreach (var t in m_transitions) {
+                if (dfaTable[t.s1].transitions == null)
+                    dfaTable[t.s1] = new DFAStateDescriptior(m_symbolCount, m_finalStates.Contains(t.s1));
+                
+                dfaTable[t.s1].transitions[t.edge] = t.s2;
+            }
+
+            foreach (var s in m_finalStates)
+                if (!dfaTable[s].final) 
+                    m_dfaTable[s] = new DFAStateDescriptior(m_symbolCount, true);
+                
+        }
+
+        public void SetInitialState(int s) {
+            Safe.ArgumentAssert(s >= 0, "s");
+            m_initialState = s;
+        }
+
+        public void MarkFinalState(int state) {
+            AssertNotReadOnly();
+            m_finalStates.Add(state);
+        }
+
+        public void Add(AutomatonTransition item) {
+            AssertNotReadOnly();
+            Safe.ArgumentAssert(item.s1 >= 0, "item");
+            Safe.ArgumentAssert(item.s2 >= 0, "item");
+            Safe.ArgumentAssert(item.edge >= 0, "item");
+
+            m_stateCount = Math.Max(m_stateCount, Math.Max(item.s1, item.s2) + 1);
+            m_symbolCount = Math.Max(m_symbolCount, item.edge);
+
+            m_transitions.Add(item);
+        }
+
+        public void Clear() {
+            AssertNotReadOnly();
+
+            m_stateCount = 0;
+            m_symbolCount = 0;
+            m_finalStates.Clear();
+            m_transitions.Clear();
+        }
+
+        public bool Contains(AutomatonTransition item) {
+            return m_transitions.Contains(item);
+        }
+
+        public void CopyTo(AutomatonTransition[] array, int arrayIndex) {
+            m_transitions.CopyTo(array, arrayIndex);
+        }
+
+        public bool Remove(AutomatonTransition item) {
+            AssertNotReadOnly();
+            m_transitions.Remove(item);
+        }
+
+        public int Count {
+            get {
+                return m_transitions.Count;
+            }
+        }
+
+        public bool IsReadOnly {
+            get {
+                return m_dfaTable != null;
+            }
+        }
+
+        public IEnumerator<AutomatonTransition> GetEnumerator() {
+            return m_transitions.GetEnumerator();
+        }
+
+        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() {
+            return GetEnumerator();
+        }
+
+        /// <summary>Формирует множества конечных состояний перед началом работы алгоритма минимизации.</summary>
+        /// <remarks>
+        /// В процессе построения минимального автомата требуется разделить множество состояний,
+        /// на два подмножества - конечные состояния и все остальные, после чего эти подмножества
+        /// будут резделены на более мелкие. Иногда требуется гарантировать различия конечных сосотяний,
+        /// для этого необходимо переопределить даннцю фукнцию, для получения множеств конечных состояний.
+        /// </remarks>
+        /// <returns>The final states.</returns>
+        protected virtual IEnumerable<HashSet<int>> GroupFinalStates() {
+            return new HashSet<int>[] { m_finalStates };
+        }
+
+        protected void Optimize<TInput, TState>(
+            IDFATableBuilder optimalDFA,
+            IAlphabet<TInput> inputAlphabet,
+            IAlphabetBuilder<TInput> optimalInputAlphabet,
+            IAlphabet<TState> stateAlphabet,
+            IAlphabetBuilder<TState> optimalStateAlphabet
+        ) {
+            Safe.ArgumentNotNull(optimalDFA, "dfa");
+            Safe.ArgumentNotNull(optimalInputAlphabet, "optimalInputAlphabet");
+            Safe.ArgumentNotNull(optimalStateAlphabet, "optimalStateAlphabet");
+            Safe.ArgumentNotNull(inputAlphabet, "inputAlphabet");
+            Safe.ArgumentNotNull(stateAlphabet, "stateAlphabet");
+
+            if (inputAlphabet.Count != m_symbolCount)
+                throw new InvalidOperationException("The input symbols aphabet mismatch");
+            if (stateAlphabet.Count != m_stateCount)
+                throw new InvalidOperationException("The states alphabet mismatch");
+
+            var setComparer = new CustomEqualityComparer<HashSet<int>>(
+                (x, y) => x.SetEquals(y),
+                s => s.Sum(x => x.GetHashCode())
+            );
+
+            var optimalStates = new HashSet<HashSet<int>>(setComparer);
+            var queue = new HashSet<HashSet<int>>(setComparer);
+
+            // получаем конечные состояния, сгруппированные по маркерам
+            optimalStates.UnionWith(
+                GroupFinalStates()
+            );
+
+            var state = new HashSet<int>(
+                Enumerable
+                .Range(0, m_stateCount - 1)
+                .Where(i => !m_finalStates.Contains(i))
+            );
+
+            optimalStates.Add(state);
+            queue.Add(state);
+
+            var rmap = m_transitions
+                .GroupBy(t => t.s2)
+                .ToLookup(
+                    g => g.Key, // s2
+                    g => g.ToLookup(t => t.edge, t => t.s1)
+                );
+
+            while (queue.Count > 0) {
+                var stateA = queue.First();
+                queue.Remove(stateA);
+
+                for (int c = 0; c < m_symbolCount; c++) {
+                    var stateX = new HashSet<int>();
+                    foreach(var a in stateA)
+                        stateX.UnionWith(rmap[a][c]); // all states from wich 'c' leads to 'a'
+
+                    foreach (var stateY in optimalStates.ToArray()) {
+                        if (stateX.Overlaps(stateY) && !stateY.IsSubsetOf(stateX)) {
+                            var stateR1 = new HashSet<int>(stateY);
+                            var stateR2 = new HashSet<int>(stateY);
+
+                            stateR1.IntersectWith(stateX);
+                            stateR2.ExceptWith(stateX);
+
+                            optimalStates.Remove(stateY);
+                            optimalStates.Add(stateR1);
+                            optimalStates.Add(stateR2);
+
+                            if (queue.Contains(stateY)) {
+                                queue.Remove(stateY);
+                                queue.Add(stateR1);
+                                queue.Add(stateR2);
+                            } else {
+                                queue.Add(stateR1.Count <= stateR2.Count ? stateR1 : stateR2);
+                            }
+                        }
+                    }
+                }
+            }
+
+            // карта получения оптимального состояния по соотвествующему ему простому состоянию
+            var statesMap = stateAlphabet.Reclassify(optimalStateAlphabet, optimalStates);
+
+            // получаем минимальный алфавит
+            // входные символы не различимы, если Move(s,a1) == Move(s,a2)
+            var optimalAlphabet = m_transitions
+                .GroupBy(t => Tuple.Create(statesMap[t.s1], statesMap[t.s2]), t => t.edge);
+
+            var alphabetMap = inputAlphabet.Reclassify(optimalInputAlphabet, optimalAlphabet);
+
+            // построение автомата
+            optimalDFA.SetInitialState(statesMap[m_initialState]);
+
+            foreach (var sf in m_finalStates.GroupBy(s => statesMap[s]))
+                optimalDFA.MarkFinalState(sf.Key);
+
+            foreach (var t in m_transitions.Select(t => new AutomatonTransition(statesMap[t.s1],statesMap[t.s2],alphabetMap[t.edge])).Distinct())
+                optimalDFA.Add(t);
+
+        }
+
+        protected void PrintDFA<TInput, TState>(IAlphabet<TInput> inputAlphabet, IAlphabet<TState> stateAlphabet) {
+            Safe.ArgumentNotNull(inputAlphabet, "inputAlphabet");
+            Safe.ArgumentNotNull(stateAlphabet, "stateAlphabet");
+
+            var inputMap = inputAlphabet.CreateReverseMap();
+            var stateMap = stateAlphabet.CreateReverseMap();
+
+            for (int i = 0; i < inputMap.Length; i++) 
+                Console.WriteLine("C{0}: {1}", i, String.Join(",", inputMap[i]));
+            
+
+            foreach(var t in m_transitions)
+                Console.WriteLine(
+                    "[{0}] -{{{1}}}-> [{2}]{3}",
+                    stateMap[t.s1],
+                    String.Join(",", inputMap[t.edge]),
+                    stateMap[t.s2],
+                    m_finalStates.Contains(t.s2) ? "$" : ""
+                );
+
+        }
+
+    }
+}