optimize vector initialization

src/Pieces/Polyomino.cpp

@@ -78,15 +78,8 @@ void Polyomino::rotateCCW() {
 
 void Polyomino::goToSpawnPosition() {
     // initialize array
-    std::vector<std::vector<int>> linesCompleteness;
-    linesCompleteness.reserve(4);
-    std::vector<int> empty;
-    for (int j = 0; j < this->length; j++) {
-        empty.push_back(0);
-    }
-    for (int i = 0; i < 4; i++) {
-        linesCompleteness.push_back(empty);
-    }
+    std::vector<int> empty(this->length, 0);
+    std::vector<std::vector<int>> linesCompleteness(4, empty);
 
     // calculates amount of squares per rows and columns
     for (const Position position : *this) {