Fix unnecessary memory allocations for permutations.

include/interac_list.txx

@@ -292,15 +292,19 @@ Permutation<typename Node_t::Real_t>& InteracList<Node_t>::Perm_R(int l, Mat_Typ
   if(row_perm.Dim()==0){
     std::vector<Perm_Type> p_list=PermutList(type, indx);
     for(int i=0;i<l;i++) p_list.push_back(Scaling);
-    row_perm=Permutation<Real_t>(M0.Dim(0));
+    Permutation<Real_t> row_perm_=Permutation<Real_t>(M0.Dim(0));
+    for(int i=0;i<C_Perm;i++){
+      Permutation<Real_t>& pr=mat->Perm(type, R_Perm + i);
+      if(!pr.Dim()) row_perm_=Permutation<Real_t>(0);
+    }
+
+    if(row_perm_.Dim()>0)
     for(int i=p_list.size()-1; i>=0; i--){
+      assert(type!=V_Type);
       Permutation<Real_t>& pr=mat->Perm(type, R_Perm + p_list[i]);
-      if(pr.Dim()!=M0.Dim(0)){
-        row_perm=Permutation<Real_t>(indx==indx0?M0.Dim(0):0);
-        break;
-      }
-      row_perm=pr.Transpose()*row_perm;
+      row_perm_=pr.Transpose()*row_perm_;
     }
+    row_perm=row_perm_;
   }
   return row_perm;
 }
@@ -316,15 +320,19 @@ Permutation<typename Node_t::Real_t>& InteracList<Node_t>::Perm_C(int l, Mat_Typ
   if(col_perm.Dim()==0){
     std::vector<Perm_Type> p_list=PermutList(type, indx);
     for(int i=0;i<l;i++) p_list.push_back(Scaling);
-    col_perm=Permutation<Real_t>(M0.Dim(1));
+    Permutation<Real_t> col_perm_=Permutation<Real_t>(M0.Dim(1));
+    for(int i=0;i<C_Perm;i++){
+      Permutation<Real_t>& pc=mat->Perm(type, C_Perm + i);
+      if(!pc.Dim()) col_perm_=Permutation<Real_t>(0);
+    }
+
+    if(col_perm_.Dim()>0)
     for(int i=p_list.size()-1; i>=0; i--){
+      assert(type!=V_Type);
       Permutation<Real_t>& pc=mat->Perm(type, C_Perm + p_list[i]);
-      if(pc.Dim()!=M0.Dim(1)){
-        col_perm=Permutation<Real_t>(indx==indx0?M0.Dim(1):0);
-        break;
-      }
-      col_perm=col_perm*pc;
+      col_perm_=col_perm_*pc;
     }
+    col_perm=col_perm_;
   }
   return col_perm;
 }