Stop pushing on the vector

For better performance

sa.hpp

@@ -58,6 +58,9 @@ class solution {
 			 	 its.insert(i);
 			 }
 
+			 this->items.resize(items.size());
+			 size_t i = 0;
+
 			 long long cap = capacity;
 
 			while (!its.empty()) {
@@ -65,14 +68,14 @@ class solution {
 				if (itr == its.begin()) {
 	        			cap = capacity;
 	        			cap -= *its.begin();
-	         	 	 	 this->items.push_back(*its.begin());
-	         	 	 	 its.erase(its.begin());
-	         	 	 	 continue;
-	         	 	 }
+	        			itr = its.begin();
+				} else {
 					itr--;
 					cap -= *itr;
-	         	 	 this->items.push_back(*itr);
+				}
+				this->items[i] = *itr;
 				its.erase(itr);
+				i++;
 			}
 
 			fitness = calculate_boxes();