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  1. #include <iostream>
  2. #include <pthread.h>
  3. #include <random>
  4. #include <sys/time.h>
  5. using namespace std;
  6.  
  7. struct ThreadData
  8. {
  9.   int **arr;
  10.   int startRow, endRow, n;
  11.   int *sums;
  12. };
  13.  
  14. void* calculate_summ(void *arg)
  15. {
  16.   ThreadData* data = (ThreadData*)arg;
  17.  
  18.   for(int i = data->startRow; i < data->endRow; i++)
  19.   {
  20.     data->sums[i] = 0;
  21.     for(int j = 0; j < data->n; j++)
  22.     {
  23.       if(data->arr[i][j] > 0)
  24.       {
  25.         data->sums[i] += data->arr[i][j];
  26.       }
  27.     }
  28.   }
  29.   return NULL;
  30. }
  31.  
  32. struct timeval tv1;
  33. void time_start()
  34. {
  35.   struct timezone tz;
  36.   gettimeofday(&tv1, &tz);
  37. }
  38.  
  39. long time_stop()
  40. {
  41.   struct timeval tv2, dtv;
  42.   struct timezone tz;
  43.   gettimeofday(&tv2, &tz);
  44.   dtv.tv_sec= tv2.tv_sec -tv1.tv_sec;
  45.   dtv.tv_usec=tv2.tv_usec-tv1.tv_usec;
  46.   if(dtv.tv_usec<0) 
  47.   {
  48.      dtv.tv_sec--;
  49.      dtv.tv_usec+=1000000;
  50.   }
  51.   return dtv.tv_sec*1000000+dtv.tv_usec;
  52. }
  53.  
  54. int main()
  55. {
  56.   srand(time(0));
  57.  
  58.   int n = 100, m = 100, k = 2;
  59.  
  60.   int** arr = new int*[n];
  61.   for(int i = 0; i < n; i++)
  62.   {
  63.     arr[i] = new int[m];
  64.   }
  65.   for(int i = 0; i < n; i++)
  66.   {
  67.     for(int j = 0; j < m; j++)
  68.     {
  69.       arr[i][j] = rand()%15-5;
  70.     }
  71.   }
  72.   /*
  73.   for(int i = 0; i < n; i++)
  74.   {
  75.     for(int j = 0; j < m; j++)
  76.     {
  77.       cout << arr[i][j] << " ";
  78.     }
  79.     cout << endl;
  80.   }
  81.   */
  82.   int thread_num = n/k, ostatok = n%k, sums[n];
  83.  
  84.   time_start();
  85.  
  86.   pthread_t* threads = new pthread_t[thread_num];
  87.   ThreadData* threadData = new ThreadData[thread_num];
  88.  
  89.   for(int i = 0; i < thread_num; i++)
  90.   {
  91.     threadData[i].n = n;
  92.     threadData[i].startRow = i*k;
  93.     threadData[i].endRow = threadData[i].startRow + k;
  94.     threadData[i].arr = arr;
  95.     threadData[i].sums = sums;
  96.  
  97.     pthread_create(&threads[i], NULL, calculate_summ, (void*)&threadData[i]);
  98.   }
  99.  
  100.   for(int i = 0; i < ostatok; i++) {
  101.    threadData[i].endRow += 1;
  102. }
  103.  
  104.   for(int i = 0; i < thread_num; i++)
  105.   {
  106.     pthread_join(threads[i], NULL);
  107.   }
  108.   /*
  109.   cout << "sums: ";
  110.   for(int i = 0; i < n; i++)
  111.   {
  112.     cout << sums[i] << " ";
  113.   }
  114.   */
  115.   cout << "\nPARAL_GROUP: Time: " << time_stop() << endl;
  116.  
  117.   for(int i = 0; i < n; i++)
  118.   {
  119.     delete[] arr[i];
  120.   }
  121.   delete[] arr;
  122.   delete[] threads;
  123.   delete[] threadData;
  124. }
  125.  
Success #stdin #stdout 0s 5288KB
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Standard input is empty
stdout
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PARAL_GROUP: Time: 534
https://ideone.com/lsJHHz
language:
C++ (gcc 8.3)
created:
3 days ago
visibility:
public

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