diff --git a/OpenMP2/run.sh b/OpenMP2/run.sh
index f1405e7..93219fc 100755
--- a/OpenMP2/run.sh
+++ b/OpenMP2/run.sh
@@ -1,6 +1,6 @@
 # run.sh <number of repetitions>
 compiler="g++"
-flags="-fopenmp -std=c++11"
+flags="-Xclang -fopenmp -std=c++11 -lomp"
 src="./src/main.cpp"
 build="./build"
 exe="$build/task"
@@ -28,9 +28,9 @@ for test_dir in $tests_dir/*; do
   test=$(basename $test_dir)
   printf "\n[TEST $test]\n"
   echo "  $exe $test_dir/input.txt $build/$test.txt"
-  START=$(date +%s%N)
+  START=$(gdate +%s%N)
   $exe $test_dir/input.txt $build/$test.txt
-  END=$(date +%s%N)
+  END=$(gdate +%s%N)
   DIFF=$((($END - $START)/1000000))
   if [ ! $? -eq 0 ]; then
     echo "[TEST $test] RUNTIME FAIL"
@@ -41,9 +41,9 @@ for test_dir in $tests_dir/*; do
     RES="OK"
     if [ -n "$1" ]; then
       for ((i=1; i < $1; i++)); do
-        START=$(date +%s%N)
+        START=$(gdate +%s%N)
         $exe $test_dir/input.txt $build/${test}_$i.txt
-        END=$(date +%s%N)
+        END=$(gdate +%s%N)
         DIFF=$(($DIFF + ($END - $START)/1000000))
         if ! cmp -s $build/${test}_$i.txt $test_dir/output.txt; then
           RES="FAIL"
diff --git a/OpenMP2/src/main.cpp b/OpenMP2/src/main.cpp
index 8dab215..bc0c25f 100644
--- a/OpenMP2/src/main.cpp
+++ b/OpenMP2/src/main.cpp
@@ -3,47 +3,50 @@
 #include <fstream>
 #include <omp.h>
 
-double calc(uint32_t x_last, uint32_t num_threads)
-{
-  return 0;
+double calc(uint32_t x_last, uint32_t num_threads) {
+    double res = 0.0;
+#pragma omp parallel for num_threads(num_threads)
+    {
+        for (int i = x_last; i > 0; i--) {
+            double f = i;
+            res += 1.0 / f;
+        }
+    }
+    return res;
 }
 
-int main(int argc, char** argv)
-{
-  // Check arguments
-  if (argc != 3)
-  {
-    std::cout << "[Error] Usage <inputfile> <output file>\n";
-    return 1;
-  }
+int main(int argc, char **argv) {
+    // Check arguments
+    if (argc != 3) {
+        std::cout << "[Error] Usage <inputfile> <output file>\n";
+        return 1;
+    }
 
-  // Prepare input file
-  std::ifstream input(argv[1]);
-  if (!input.is_open())
-  {
-    std::cout << "[Error] Can't open " << argv[1] << " for write\n";
-    return 1;
-  }
+    // Prepare input file
+    std::ifstream input(argv[1]);
+    if (!input.is_open()) {
+        std::cout << "[Error] Can't open " << argv[1] << " for write\n";
+        return 1;
+    }
 
-  // Prepare output file
-  std::ofstream output(argv[2]);
-  if (!output.is_open())
-  {
-    std::cout << "[Error] Can't open " << argv[2] << " for read\n";
-    input.close();
-    return 1;
-  }
+    // Prepare output file
+    std::ofstream output(argv[2]);
+    if (!output.is_open()) {
+        std::cout << "[Error] Can't open " << argv[2] << " for read\n";
+        input.close();
+        return 1;
+    }
 
-  // Read arguments from input
-  uint32_t x_last = 0, num_threads = 0;
-  input >> x_last >> num_threads;
-  // Calculation
-  double res = calc(x_last, num_threads);
+    // Read arguments from input
+    uint32_t x_last = 0, num_threads = 0;
+    input >> x_last >> num_threads;
+    // Calculation
+    double res = calc(x_last, num_threads);
 
-  // Write result
-  output << std::setprecision(15) << res << std::endl;
-  // Prepare to exit
-  output.close();
-  input.close();
-  return 0;
+    // Write result
+    output << std::setprecision(15) << res << std::endl;
+    // Prepare to exit
+    output.close();
+    input.close();
+    return 0;
 }
diff --git a/OpenMP3/run.sh b/OpenMP3/run.sh
index f1405e7..93219fc 100755
--- a/OpenMP3/run.sh
+++ b/OpenMP3/run.sh
@@ -1,6 +1,6 @@
 # run.sh <number of repetitions>
 compiler="g++"
-flags="-fopenmp -std=c++11"
+flags="-Xclang -fopenmp -std=c++11 -lomp"
 src="./src/main.cpp"
 build="./build"
 exe="$build/task"
@@ -28,9 +28,9 @@ for test_dir in $tests_dir/*; do
   test=$(basename $test_dir)
   printf "\n[TEST $test]\n"
   echo "  $exe $test_dir/input.txt $build/$test.txt"
-  START=$(date +%s%N)
+  START=$(gdate +%s%N)
   $exe $test_dir/input.txt $build/$test.txt
-  END=$(date +%s%N)
+  END=$(gdate +%s%N)
   DIFF=$((($END - $START)/1000000))
   if [ ! $? -eq 0 ]; then
     echo "[TEST $test] RUNTIME FAIL"
@@ -41,9 +41,9 @@ for test_dir in $tests_dir/*; do
     RES="OK"
     if [ -n "$1" ]; then
       for ((i=1; i < $1; i++)); do
-        START=$(date +%s%N)
+        START=$(gdate +%s%N)
         $exe $test_dir/input.txt $build/${test}_$i.txt
-        END=$(date +%s%N)
+        END=$(gdate +%s%N)
         DIFF=$(($DIFF + ($END - $START)/1000000))
         if ! cmp -s $build/${test}_$i.txt $test_dir/output.txt; then
           RES="FAIL"
diff --git a/OpenMP3/src/main.cpp b/OpenMP3/src/main.cpp
index 1ca5a7a..0c76bc0 100644
--- a/OpenMP3/src/main.cpp
+++ b/OpenMP3/src/main.cpp
@@ -2,10 +2,37 @@
 #include <iomanip>
 #include <fstream>
 #include <omp.h>
+#include <math.h>
+double func(double x) {
+    return sin(x);
+}
+
+double create_task(float a, float b, float dx) {
+    double res = 0;
+    int len = (int) ((b - a) / dx);
+    for (int i = 0; i < len; i++) {
+        double x = a + (double) i * dx + dx / 2;
+        res += dx * func(x);
+    }
+    return res;
+}
 
 double calc(double x0, double x1, double dx, uint32_t num_threads)
 {
-  return 0;
+    float dx_thread = (x1 - x0) / num_threads;
+    int len = (int) ((x1 - x0) / dx);
+    double res = 0;
+#pragma omp parallel for num_threads(num_threads) reduction(+:res)
+    {
+        for (int i = 0; i < num_threads; i++) {
+            res += create_task(x0 + i * dx_thread, x0 + (i + 1) * dx_thread, dx);
+        }
+//        for (int i = 0; i < len; i++) {
+//            double x = x0 + (double) i * dx + dx / 2;
+//            res += dx * func(x);
+//        }
+    }
+  return round(res);
 }
 
 int main(int argc, char** argv)
@@ -43,7 +70,7 @@ int main(int argc, char** argv)
   double res = calc(x0, x1, dx, num_threads);
 
   // Write result
-  output << std::setprecision(15) << res;
+  output << std::setprecision(15) << res << std::endl;
   // Prepare to exit
   output.close();
   input.close();
diff --git a/OpenMP4/run.sh b/OpenMP4/run.sh
index f1405e7..93219fc 100755
--- a/OpenMP4/run.sh
+++ b/OpenMP4/run.sh
@@ -1,6 +1,6 @@
 # run.sh <number of repetitions>
 compiler="g++"
-flags="-fopenmp -std=c++11"
+flags="-Xclang -fopenmp -std=c++11 -lomp"
 src="./src/main.cpp"
 build="./build"
 exe="$build/task"
@@ -28,9 +28,9 @@ for test_dir in $tests_dir/*; do
   test=$(basename $test_dir)
   printf "\n[TEST $test]\n"
   echo "  $exe $test_dir/input.txt $build/$test.txt"
-  START=$(date +%s%N)
+  START=$(gdate +%s%N)
   $exe $test_dir/input.txt $build/$test.txt
-  END=$(date +%s%N)
+  END=$(gdate +%s%N)
   DIFF=$((($END - $START)/1000000))
   if [ ! $? -eq 0 ]; then
     echo "[TEST $test] RUNTIME FAIL"
@@ -41,9 +41,9 @@ for test_dir in $tests_dir/*; do
     RES="OK"
     if [ -n "$1" ]; then
       for ((i=1; i < $1; i++)); do
-        START=$(date +%s%N)
+        START=$(gdate +%s%N)
         $exe $test_dir/input.txt $build/${test}_$i.txt
-        END=$(date +%s%N)
+        END=$(gdate +%s%N)
         DIFF=$(($DIFF + ($END - $START)/1000000))
         if ! cmp -s $build/${test}_$i.txt $test_dir/output.txt; then
           RES="FAIL"
diff --git a/OpenMP4/src/main.cpp b/OpenMP4/src/main.cpp
index aa92f69..b8f1928 100644
--- a/OpenMP4/src/main.cpp
+++ b/OpenMP4/src/main.cpp
@@ -3,46 +3,59 @@
 #include <fstream>
 #include <omp.h>
 
-double calc()
-{
-  return 0;
+double calc(uint32_t x_last, uint32_t num_threads) {
+    double fct = 1;
+    double *facts = (double *) malloc(sizeof(double) * x_last);
+    facts[0] = 1;
+    double start = omp_get_wtime();
+    for (int i = 1; i <= x_last; i++) {
+        fct *= (double) i;
+        facts[i] = fct;
+    }
+    double res = 0;
+#pragma omp parallel for num_threads(num_threads) reduction(+:res)
+    {
+        for (int i = x_last - 1; i >= 0; i--) {
+            res += 1 / facts[i];
+        }
+    }
+    free(facts);
+    return res;
 }
 
-int main(int argc, char** argv)
-{
-  // Check arguments
-  if (argc != 3)
-  {
-    std::cout << "[Error] Usage <inputfile> <output file>\n";
-    return 1;
-  }
+int main(int argc, char **argv) {
+    // Check arguments
+    if (argc != 3) {
+        std::cout << "[Error] Usage <inputfile> <output file>\n";
+        return 1;
+    }
 
-  // Prepare input file
-  std::ifstream input(argv[1]);
-  if (!input.is_open())
-  {
-    std::cout << "[Error] Can't open " << argv[1] << " for write\n";
-    return 1;
-  }
+    // Prepare input file
+    std::ifstream input(argv[1]);
+    if (!input.is_open()) {
+        std::cout << "[Error] Can't open " << argv[1] << " for write\n";
+        return 1;
+    }
 
-  // Prepare output file
-  std::ofstream output(argv[2]);
-  if (!output.is_open())
-  {
-    std::cout << "[Error] Can't open " << argv[2] << " for read\n";
-    input.close();
-    return 1;
-  }
+    // Prepare output file
+    std::ofstream output(argv[2]);
+    if (!output.is_open()) {
+        std::cout << "[Error] Can't open " << argv[2] << " for read\n";
+        input.close();
+        return 1;
+    }
 
-  // Read arguments from input
+// Read arguments from input
+    uint32_t x_last = 0, num_threads = 0;
+    input >> x_last >> num_threads;
 
-  // Calculation
-  double res = calc();
+    // Calculation
+    double res = calc(x_last, num_threads);
 
-  // Write result
-  output << std::setprecision(15) << res;
-  // Prepare to exit
-  output.close();
-  input.close();
-  return 0;
+    // Write result
+    output << std::setprecision(15) << res << std::endl;
+    // Prepare to exit
+    output.close();
+    input.close();
+    return 0;
 }
diff --git a/OpenMP4/tests/00/input.txt b/OpenMP4/tests/00/input.txt
new file mode 100644
index 0000000..2fb73a0
--- /dev/null
+++ b/OpenMP4/tests/00/input.txt
@@ -0,0 +1 @@
+1 1
diff --git a/OpenMP4/tests/00/output.txt b/OpenMP4/tests/00/output.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/OpenMP4/tests/00/output.txt
@@ -0,0 +1 @@
+1
diff --git a/OpenMP4/tests/01/input.txt b/OpenMP4/tests/01/input.txt
new file mode 100644
index 0000000..9ebabbc
--- /dev/null
+++ b/OpenMP4/tests/01/input.txt
@@ -0,0 +1 @@
+1 8
diff --git a/OpenMP4/tests/01/output.txt b/OpenMP4/tests/01/output.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/OpenMP4/tests/01/output.txt
@@ -0,0 +1 @@
+1
diff --git a/OpenMP4/tests/02/input.txt b/OpenMP4/tests/02/input.txt
new file mode 100644
index 0000000..cba3471
--- /dev/null
+++ b/OpenMP4/tests/02/input.txt
@@ -0,0 +1 @@
+2 1
diff --git a/OpenMP4/tests/02/output.txt b/OpenMP4/tests/02/output.txt
new file mode 100644
index 0000000..0cfbf08
--- /dev/null
+++ b/OpenMP4/tests/02/output.txt
@@ -0,0 +1 @@
+2
diff --git a/OpenMP4/tests/03/input.txt b/OpenMP4/tests/03/input.txt
new file mode 100644
index 0000000..c0be89e
--- /dev/null
+++ b/OpenMP4/tests/03/input.txt
@@ -0,0 +1 @@
+2 8
diff --git a/OpenMP4/tests/03/output.txt b/OpenMP4/tests/03/output.txt
new file mode 100644
index 0000000..0cfbf08
--- /dev/null
+++ b/OpenMP4/tests/03/output.txt
@@ -0,0 +1 @@
+2
diff --git a/OpenMP4/tests/04/input.txt b/OpenMP4/tests/04/input.txt
new file mode 100644
index 0000000..28ba9b1
--- /dev/null
+++ b/OpenMP4/tests/04/input.txt
@@ -0,0 +1 @@
+10000 1
diff --git a/OpenMP4/tests/04/output.txt b/OpenMP4/tests/04/output.txt
new file mode 100644
index 0000000..ebb4380
--- /dev/null
+++ b/OpenMP4/tests/04/output.txt
@@ -0,0 +1 @@
+2.71828182845905
diff --git a/OpenMP4/tests/05/input.txt b/OpenMP4/tests/05/input.txt
new file mode 100644
index 0000000..b22a23c
--- /dev/null
+++ b/OpenMP4/tests/05/input.txt
@@ -0,0 +1 @@
+10000 8
diff --git a/OpenMP4/tests/05/output.txt b/OpenMP4/tests/05/output.txt
new file mode 100644
index 0000000..ebb4380
--- /dev/null
+++ b/OpenMP4/tests/05/output.txt
@@ -0,0 +1 @@
+2.71828182845905
diff --git a/OpenMP4/tests/06/input.txt b/OpenMP4/tests/06/input.txt
new file mode 100644
index 0000000..1e24de6
--- /dev/null
+++ b/OpenMP4/tests/06/input.txt
@@ -0,0 +1 @@
+100000000 1
diff --git a/OpenMP4/tests/06/output.txt b/OpenMP4/tests/06/output.txt
new file mode 100644
index 0000000..ebb4380
--- /dev/null
+++ b/OpenMP4/tests/06/output.txt
@@ -0,0 +1 @@
+2.71828182845905
diff --git a/OpenMP4/tests/07/input.txt b/OpenMP4/tests/07/input.txt
new file mode 100644
index 0000000..9e049b3
--- /dev/null
+++ b/OpenMP4/tests/07/input.txt
@@ -0,0 +1 @@
+100000000 8
diff --git a/OpenMP4/tests/07/output.txt b/OpenMP4/tests/07/output.txt
new file mode 100644
index 0000000..ebb4380
--- /dev/null
+++ b/OpenMP4/tests/07/output.txt
@@ -0,0 +1 @@
+2.71828182845905