Reduce graph regex matching time with the help of @vincentlorrain

src/graphRegex/GraphRegex.cpp

 #include "aidge/graphRegex/GraphRegex.hpp"
-using namespace Aidge; 
+using namespace Aidge;
 
 
 void GraphRegex::setKeyFromGraph(std::shared_ptr<GraphView> ref){
@@ -27,7 +27,7 @@ void GraphRegex::setKeyFromGraph(std::shared_ptr<GraphView> ref){
 
 
 // void GraphRegex::addQuery(const std::string query){
-//     //TODO one query only but the same string is a same query but 
+//     //TODO one query only but the same string is a same query but
 //     //2 different string it's maybe the same query , we need to check the AST
 //     mQueryRecipe[query] = nullptr;
 // }
@@ -52,7 +52,7 @@ void GraphRegex::_generateCombinationsStart(const std::set<NodePtr>& elements, s
     }
 }
 
-
+// factorial(n) tree searched optimized with a stopping condition
 void GraphRegex::_findLargestCompatibleSet(
     const std::vector<std::shared_ptr<MatchSolution>>& solutions,
     std::set<std::shared_ptr<MatchSolution>>& currentSet,
@@ -75,6 +75,10 @@ void GraphRegex::_findLargestCompatibleSet(
             currentSet.insert(solutions[i]);
             _findLargestCompatibleSet(solutions, currentSet, largestSet, i + 1);
             currentSet.erase(solutions[i]);
+            // cut the size of the graph of possibilities
+            if ((currentSet.size() + solutions.size() - currentIndex) <= largestSet.size()) {
+                return;
+            }
         }
     }
 }
@@ -101,14 +105,14 @@ std::set<std::shared_ptr<MatchSolution>> GraphRegex::match(std::shared_ptr<Graph
         std::shared_ptr<GraphFsmInterpreter>  fsmGenerator = std::make_shared<GraphFsmInterpreter>(query,mAllTest);
         std::shared_ptr<FsmGraph> fsm = fsmGenerator->interpret();
 
-        // generate all the start possibility 
+        // generate all the start possibility
         std::size_t nb_startSt =  fsm->getNbStart();
         std::set<std::vector<NodePtr>> combinations;
         std::vector<NodePtr> current;
         _generateCombinationsStart(ref->getNodes(), nb_startSt, 0, current, combinations);
-        
 
-        // all start 
+
+        // all start
         for (const auto& combination : combinations) {
             std::vector<std::shared_ptr<MatchSolution>> solution = fsm->test(combination);
             solutions.insert(solutions.end(), solution.begin(), solution.end());
@@ -133,7 +137,7 @@ void GraphRegex::setNodeKey(const std::string key, const std::string conditional
 
 
 void GraphRegex::setNodeKey(const std::string key,std::function<bool(NodePtr)> f){
-    //we can applied to all key but it's not efficient 
+    //we can applied to all key but it's not efficient
     if(mAllLambda.find(key) != mAllLambda.end()){
         throw std::runtime_error(key + " is define");
     }
@@ -142,7 +146,7 @@ void GraphRegex::setNodeKey(const std::string key,std::function<bool(NodePtr)> f
 }
 
 void GraphRegex::_majConditionalInterpreterLambda(){
-       
+
     for (const auto& test : mAllTest) {
         for (const auto& pair : mAllLambda) {
             const std::string& key = pair.first;
@@ -151,7 +155,7 @@ void GraphRegex::_majConditionalInterpreterLambda(){
             if(!test->isLambdaRegister(key)){
                 test->insertLambda(key,lambda);
             }
-            
+
         }
     }
 }