diff --git a/Reverse.cpp b/Reverse.cpp
index 135757a..c3e50fd 100644
--- a/Reverse.cpp
+++ b/Reverse.cpp
@@ -6,7 +6,7 @@ std::string Reverse::reverse(std::string& toReverse)
 
     for(std::string::reverse_iterator rit=toReverse.rbegin(); rit!=toReverse.rend(); ++rit)
     {
-        ret.insert(ret.end(), *rit);
+        ret.push_back(*rit);
     }
     return ret;
-}
+}
\ No newline at end of file
diff --git a/f1.cpp b/f1.cpp
index 97ea106..9a639c9 100644
--- a/f1.cpp
+++ b/f1.cpp
@@ -13,34 +13,32 @@ using namespace std;
 
 bool F1::run()
 {
-
     std::cout << "f1" << std::endl;
 
-    int N, K;
-
-    N = 10000;
-    K = 10000;
+    int N = 10000, K = 10000;
 
     int total = ((N - 1) * (N - 2)) / 2;
     if (K > total)
     {
-        cout << -1 << endl;
-        return 0;
+        std::cout << -1 << std::endl;
+        return false;
     }
 
-    vector<pair<int, int>> edges;
+    std::vector<std::pair<int, int>> edges;
+    edges.reserve(N - 1 + total - K); // Reserve memory to avoid reallocations
+
     for (int i = 2; i <= N; ++i)
     {
-        edges.push_back({1, i});
+        edges.emplace_back(1, i);
     }
 
     for (int i = 2; i < N && total > K; ++i)
     {
         for (int j = i + 1; j <= N && total > K; ++j, --total)
         {
-            edges.push_back({i, j});
+            edges.emplace_back(i, j);
         }
     }
 
     return true;
-}
+}
\ No newline at end of file
diff --git a/high_load.cpp b/high_load.cpp
index 836fe26..8bafa33 100644
--- a/high_load.cpp
+++ b/high_load.cpp
@@ -1,3 +1,4 @@
+#include <random>
 #include "high_load.h"
 
 #include <bits/stdc++.h>
@@ -10,22 +11,27 @@ typedef long long ll;
 using namespace std;
 
 
-bool BenchmarkRunner::benchmark(){
-        srand( (unsigned)time(NULL) );
-        for(int i=0;i<5000;i++) {
-            boost::container::flat_map<int, int> test_map;
-            boost::container::stable_vector<int> test_keys;
-            // Insert random keys
-            for (int i = 0; i < 1000; i++) {
-                int random_key = rand() % 100000;
-                test_map[random_key] = 0;
-                test_keys.push_back(random_key);
-            }
-
-            for (int key : test_keys) {
-                test_map[key] += 1;
-            }
-            map<int, int> m;
+bool BenchmarkRunner::benchmark() {
+    std::random_device rd;
+    std::mt19937 gen(rd());
+    std::uniform_int_distribution<int> dis(0, 99999);
+
+    for (int i = 0; i < 5000; i++) {
+        boost::container::flat_map<int, int> test_map;
+        std::vector<int> test_keys;
+        test_keys.reserve(1000);
+
+        // Insert random keys
+        for (int j = 0; j < 1000; j++) {
+            int random_key = dis(gen);
+            test_map.emplace(random_key, 0);
+            test_keys.emplace_back(random_key);
+        }
+
+        for (int key : test_keys) {
+            test_map[key] += 1;
         }
-        return true;
-}
+        std::map<int, int> m;
+    }
+    return true;
+}
\ No newline at end of file
diff --git a/post_test.sh b/post_test.sh
old mode 100755
new mode 100644