#include <stdlib.h>
#include <inttypes.h>
#include <sys/sem.h>
#include <sys/shm.h>
#include <sys/ipc.h>
#include <unistd.h>
#include <stdio.h>


enum { DECIMAL_BASE = 10 };

int
main(int argc, char *argv[])
{
    pid_t pid;
    int nproc = strtol(argv[1], NULL, DECIMAL_BASE);
    int key = strtol(argv[2], NULL, DECIMAL_BASE);
    int maxval = strtoull(argv[3], NULL, DECIMAL_BASE);
    int shm_id, sem_id;
    if ((shm_id = shmget(key, 3 * sizeof(maxval), IPC_CREAT | 0600)) == -1) {
        return 1;
    }
    int *memory = shmat(shm_id, NULL, 0);
    if (memory == NULL) {
        return 1;
    }
    if ((sem_id = semget(key, nproc, IPC_CREAT | 0600)) == -1) {
        return 1;
    }

    for (int i = 0; i < nproc; ++i) {
        pid = fork();
        if (pid == -1) {
            return 1;
        } else if (!pid) {
            int value, target;
            struct sembuf lock = {i, -1, 0};
            struct sembuf unlock = {-1, 1, 0};
            while (1) {
                if (semop(sem_id, &lock, 1) == -1) {
                    _exit(0);
                }
                value = memory[1];
                value++;
                printf("%d %d %d\n", memory[0], memory[1], memory[2]);
                fflush(stdout);
                if (value > maxval) {
                    semctl(sem_id, 1, IPC_RMID, 0);
                    _exit(0);
                } else {
                    target = ((value%nproc)*(value%nproc)*
                            (value%nproc)*(value%nproc))%nproc;
                    unlock.sem_num = target;
                    memory[0] = target+1;
                    memory[1] = value;
                    memory[2] = i+1;
                    semop(sem_id, &unlock, 1);
                }
            }
        }
    }
    struct sembuf unlock = {0, 1, 0};
    memory[0] = 1;
    memory[1] = 0;
    memory[2] = 0;
    semop(sem_id, &unlock, 1);
    while (wait(NULL) > 0) {}
    shmctl(shm_id, IPC_RMID, NULL);

    return 0;
}