diff --git a/deltapq_approx_tree_main.cpp b/deltapq_approx_tree_main.cpp
index 338e30f..955c6f4 100644
--- a/deltapq_approx_tree_main.cpp
+++ b/deltapq_approx_tree_main.cpp
@@ -246,6 +246,11 @@ int main(int argc, char* argv[]){
         int M_arg;
         M_arg = PQ_M + sizeof(int);
         diff_argument = PQ_M + sizeof(int);
+        m_sub_distances = new float*[PQ_M]; // m_sub_distances defined in .h file
+        for (int i = 0; i < PQ_M; i++) {
+            m_sub_distances[i] = new float[PQ_K];
+            memset(m_sub_distances[i], 0, sizeof(float)*PQ_K);
+        }
         bool file_read = create_approx_tree(dataset, vecs, dummycodes, 
                         dummymarks, M_arg, PQ_K, num_codes, diff_argument, 
                         nodes, m_sub_distances,
diff --git a/pq_tree.cpp b/pq_tree.cpp
index d37c6b4..6eac5c1 100644
--- a/pq_tree.cpp
+++ b/pq_tree.cpp
@@ -391,9 +391,6 @@ vector<pair<int, float> > PQTree::SampledQuery(vector<float> &query, int id) {
     return results;
 }
 #ifdef PLAIN_PQ
-auto comp_max_heap = [](const pair<int, float> &a, const pair<int, float> &b) {
-    return a.second < b.second;
-};
 void print_heap(vector<pair<int, float>>& test) {
     for (int i = 0; i < test.size(); i ++) {
         cout << test[i].first << ", " << test[i].second << "    ";