diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..e69de29
diff --git a/drama/src/rev-mc.c b/drama/src/rev-mc.c
index 3c52ace..9564d14 100644
--- a/drama/src/rev-mc.c
+++ b/drama/src/rev-mc.c
@@ -11,6 +11,7 @@
 
 
 #include <vector>
+#include <set>
 #include <functional>
 #include <algorithm>
 #include <bitset>  
@@ -37,6 +38,7 @@
 typedef std::vector<addr_tuple> set_t; 
 
 //-------------------------------------------
+bool is_in(char* val, std::set<char*> arr);
 bool is_in(char* val, std::vector<char*> arr);
 bool found_enough(std::vector<set_t> sets, uint64_t set_cnt, size_t set_size);
 void filter_sets(std::vector<set_t>& sets, size_t set_size);
@@ -44,9 +46,11 @@ void print_sets(std::vector<set_t> sets);
 void verify_sets(std::vector<set_t>& sets, uint64_t threshold, size_t rounds);
 
 //-------------------------------------------
+static std::vector<uint64_t> time_vals;
 uint64_t time_tuple(volatile char* a1, volatile char* a2, size_t rounds) {
 
-    uint64_t* time_vals = (uint64_t*) calloc(rounds, sizeof(uint64_t));
+    // uint64_t* time_vals = (uint64_t*) calloc(rounds, sizeof(uint64_t));
+    time_vals.resize(rounds);
     uint64_t t0;
     sched_yield();
     for (size_t i = 0; i < rounds; i++) {
@@ -61,8 +65,8 @@ uint64_t time_tuple(volatile char* a1, volatile char* a2, size_t rounds) {
 
     }
 
-    uint64_t mdn = median(time_vals, rounds);
-    free(time_vals);
+    uint64_t mdn = median(time_vals.data(), rounds);
+    // free(time_vals);
     return mdn;
 }
 
@@ -318,6 +322,7 @@ uint64_t find_row_mask(std::vector<set_t>& sets, std::vector<uint64_t> fn_masks,
         next_mask:
         row_mask = next_bit_permutation(row_mask);
     }
+    return row_mask;
   	
    // super hackish way to recover the real row mask  
     for (auto m:fn_masks) {
@@ -340,7 +345,8 @@ void rev_mc(size_t sets_cnt, size_t threshold, size_t rounds, size_t m_size, cha
     int o_fd = 0;
     int huge_fd = 0;
     std::vector<set_t> sets;
-    std::vector<char*> used_addr;
+    // std::vector<char*> used_addr;
+    std::set<char*> used_addr;
     std::vector<uint64_t> fn_masks;
 
     srand((unsigned) time(&t));
@@ -371,7 +377,8 @@ void rev_mc(size_t sets_cnt, size_t threshold, size_t rounds, size_t m_size, cha
         if (is_in(rnd_addr, used_addr))
             continue;
 
-        used_addr.push_back(rnd_addr);
+        // used_addr.push_back(rnd_addr);
+        used_addr.insert(rnd_addr);
 
         addr_tuple tp = gen_addr_tuple(rnd_addr);
         bool found_set = false;
@@ -421,6 +428,10 @@ void rev_mc(size_t sets_cnt, size_t threshold, size_t rounds, size_t m_size, cha
 //----------------------------------------------------------
 //          Helpers
 
+bool is_in(char* val, std::set<char*> arr) {
+    return arr.find(val) != arr.end();
+}
+
 bool is_in(char* val, std::vector<char*> arr) {
     for (auto v: arr) {
         if (val == v) {