#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_key, sem_id;
    if ((shm_key = shmget(key, 3 * sizeof(int), IPC_CREAT | 0600)) == -1) {
        return 1;
    }
    int *memory = shmat(shm_key, 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) {
        if (semctl(sem_id, i, SETVAL, 0) == -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 = {-1, -1, 0};
            struct sembuf unlock = {-1, 1, 0};
            while (1) {
                while(semop(sem_id, ))
            }

        }
    }

    memory[0] = 1;
    memory[1] = 0;
    memory[2] = 0;
    while (wait(NULL) > 0) {}
    if (semctl(sem_id, 1, IPC_RMID, 0) == -1) {
        return 1;
    }

    return 0;
}