#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/times.h>

void draw(const char *txt);

int main() {
    time_t curtime = times(NULL);
    int pid = fork();
    if (pid < 0) {
        perror("Fork failed");
        return -1;
    }
    if (pid != 0) {
        printf("==> Parent: Child PID=%d\n", pid);
        srand(curtime);
        draw("Heads");
        waitpid(pid, NULL, 0);
        printf("========\n");
    } else {
        printf("==> Child\n");
        draw("Tails");
        srand(curtime + 12345678);
    }
    return 0;
}

void draw(const char *txt) {
    for (int i = 0; i < 10; ++i) {
        printf("%s\n", txt);
        int r = rand() % 2000000 + 1;
        usleep(r);
    }
}