message: Update path-sum-iv.cpp
diff: @@ -10,7 +10,7 @@ public:
  int result = 0;
  queue<node> q;
  node dummy(10);
  - node* parent_ptr = &dummy;
  + auto parent_ptr = &dummy;
  for (const auto& num : nums) {
  node child(num);
  while (!parent_ptr->isParent(child)) {
  