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

// This function will be executed by each thread
void *print_hello_world(void *tid) {
    // Print the thread's ID and a message
    printf("Hello World! Thread ID: %ld\n", (long)tid);
    pthread_exit(NULL);  // Exit the thread
}

int main(int argc, char *argv[]) {
    pthread_t threads[5]; // Array to store thread IDs
    int status;           // For storing return value of pthread_create
    long i;               // Loop variable

    // Create 5 threads
    for(i = 0; i < 5; i++) {
        printf("In main: creating thread %ld\n", i);
        // Create a new thread that will execute 'print_hello_world'
        status = pthread_create(&threads[i], NULL, print_hello_world, (void *)i);

        // Check for thread creation error
        if (status) {
            printf("Error in thread creation, return code: %d\n", status);
            exit(-1); // Exit if thread creation fails
        }
    }

    // Wait for all threads to complete
    for(i = 0; i < 5; i++) {
        pthread_join(threads[i], NULL);
    }

    printf("Program completed.\n");
    pthread_exit(NULL); // Exit the main thread
}