fix test for linkedlist

Author: bitdove

data-structures/LinkedList/__test__/test_LinkedList.cpp

@@ -188,14 +188,21 @@ int main(int argc, char* argv[]) {
   assert(list.get_at(1) == 39);
   assert(list.front() == 13);
   assert(list.back() == 21);
-  list.pop_at(2); // 13 39
+  list.push_at(2, 47); // 13 39 47 21
   assert(list.empty() == false);
-  assert(list.size() == 2);
+  assert(list.size() == 4);
   assert(list.get_at(1) == 39);
   assert(list.front() == 13);
-  assert(list.back() == 39);
+  assert(list.back() == 21);
+  list.pop_at(2); // 13 39 21
+  assert(list.empty() == false);
+  assert(list.size() == 3);
+  assert(list.get_at(1) == 39);
+  assert(list.front() == 13);
+  assert(list.back() == 21);
   list.pop_front();
   list.pop_back();
+  list.pop_back();
   assert(list.empty() == true);
   assert(list.size() == 0);
   std::cout << "ALL TEST PASSED!" << std::endl;

data-structures/LinkedList/include/LinkedList.h

@@ -100,10 +100,8 @@ void LinkedList<T>::push_at(const size_t index, const T &value){
     return;
   }
   _Node *prev = _head;
-  size_t prev_index = 0;
-  while(prev_index < index - 1){
+  for(size_t i = 0; i < index - 1; ++i){
     prev = prev->_next;
-    ++prev_index;
   }
   _Node *new_node = new _Node(value);
   new_node->_next = prev->_next;