#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>


int* data;

void* thread_func(void* arg) {
    unsigned start_index = *((int*) arg);
    unsigned array_size = *((int*) arg + 1);
    int stride = *((int*) arg + 2);
    int accessno = *((int*) arg + 3);
    unsigned element, i;
    int a = 0;
    //printf("start_index=%d array_size=%d\n", start_index,array_size);
    for (i = start_index; i < array_size; i += stride) {
        if (++a > accessno)
          break;
        //printf("  i=%d a=%d\n", i, a);
        element = data[i];
        
    }
    printf("element=%d a=%d\n", element, a-1);
    pthread_exit(NULL);
}

int main(int argc, char* argv[]) {
    unsigned array_size = 100;
    int thread_count = 1;
    int stride = 10;
    int accessno = 10;
    if (argc < 4) {
        printf("Usage: array_size thread_count stride_size access_number\n");
        return 1;
    }
    array_size = atoi(argv[1]);
    thread_count = atoi(argv[2]);
    stride = atoi(argv[3]);
    accessno = atoi(argv[4]);
    printf("Array size : %u\n", array_size);
    printf("No. threads: %d\n", thread_count);    
    printf("Stride size: %d\n", stride); 
    printf("Access num : %d\n", accessno);
    
    
    // allocate the array
    data = (unsigned*) malloc(array_size * sizeof(int));
    if (data == NULL) {
        fprintf(stderr, "Error: failed to allocate memory for the array.\n");
        exit(EXIT_FAILURE);
    }
    
    // create an array of thread ids
    pthread_t threads[thread_count];
    int thread_args[thread_count][4];
    int thread_starts[thread_count];
    for (int i = 0; i < thread_count; i++) {
        // generate a random starting index for the thread
        thread_args[i][0] = rand() % stride + i;
        thread_args[i][1] = array_size;
        thread_args[i][2] = stride;
        thread_args[i][3] = accessno;
    }

    for (int i = 0; i < thread_count; i++) 
        pthread_create(&threads[i], NULL, thread_func, (void*) &thread_args[i]);


    for (int i = 0; i < thread_count; i++)
        pthread_join(threads[i], NULL);
    

    return 0;
}