HW 1. Брылкин Дмитрий

homework/Brylkin/01/different_summing.cpp

@@ -0,0 +1,66 @@
+#include <iostream>
+#include "profile.h"
+#include <cstdint>
+#include <random>
+
+using namespace std;
+
+int main()
+{
+    std::cerr << "Starting program!" << std::endl;
+    std::random_device rd;
+    std::mt19937 gen(rd());
+    std::uniform_int_distribution<int8_t> dis(-10, 10);
+    int64_t sum1 = 0, sum2 = 0;
+    const int N = 10000;
+    int8_t** arr = new int8_t*[N];
+    for (int i = 0; i < N; ++i)
+    {
+        arr[i] = new int8_t[N];
+    }
+    std::cerr << "Memory allocated!" << std::endl;
+    for (int i = 0; i < N; ++i)
+    {
+        for (int j = 0; j < N; ++j)
+        {
+            arr[i][j] = dis(gen);
+        }
+    }
+    std::cerr << "Elements initialized!" << std::endl;
+    // считаем сумму
+    {
+        LOG_DURATION("Summing by rows");
+        for (int k = 0; k < N/100; ++k)
+        {
+            for (int i = 0; i < N; ++i)
+            {
+                for (int j = 0; j < N; ++j)
+                {
+                    sum1 += arr[i][j];
+                }
+            }
+        }
+    }
+    {
+        LOG_DURATION("Summing by cols");
+        for (int k = 0; k < N/100; ++k)
+        {
+            for (int i = 0; i < N; ++i)
+            {
+                for (int j = 0; j < N; ++j)
+                {
+                    sum2 += arr[j][i];
+                }
+            }
+        }
+    }
+    std::cerr << "Summing ended!" << std::endl;
+    for (int i = 0; i < N; ++i)
+    {
+        delete [] arr[i];
+    }
+    delete[] arr;
+    std::cerr << "Memory cleared!" << std::endl;
+    std::cout << "Sum1 = " << sum1 << "; Sum2 = " << sum2;
+    return 0;
+}

homework/Brylkin/01/profile.h

@@ -0,0 +1,38 @@
+#ifndef PROFILE_H
+#define PROFILE_H
+
+#include <chrono>
+#include <iostream>
+#include <string>
+
+using namespace std;
+using namespace std::chrono;
+
+class LogDuration {
+public:
+  explicit LogDuration(const string& msg = "")
+    : message(msg + ": ")
+    , start(steady_clock::now())
+  {
+  }
+
+  ~LogDuration() {
+    auto finish = steady_clock::now();
+    auto dur = finish - start;
+    cerr << message
+       << duration_cast<milliseconds>(dur).count()
+       << " ms" << endl;
+  }
+private:
+  string message;
+  steady_clock::time_point start;
+};
+
+#define UNIQ_ID_IMPL(lineno) _a_local_var_##lineno
+#define UNIQ_ID(lineno) UNIQ_ID_IMPL(lineno)
+
+#define LOG_DURATION(message) \
+  LogDuration UNIQ_ID(__LINE__){message};
+
+
+#endif // PROFILE_H