[wups]

Код:

forward Restart();

public OnPlayerDeath(playerid, killerid, reason)
{
    SetPVarInt(playerid, "HasDied", 1);
   new dead = DeadPlayers();
   new total = TotalPlayers();
    if(dead == total)
    {
        SetTimer("Restart", 5000, 0);
        SendClientMessageToAll(0xFFFAFA, "All the players have died, server will restart in 5 seconds!");
    }
    return 1;
}

public Restart()
{
    SendRconCommand("gmx");
    return 1;
}

stock DeadPlayers()
{
    new deadplayers;
    for(new x=0; x<MAX_PLAYERS; x++)
    {
        if(GetPVarInt(x, "HasDied") == 1) deadplayers++;
    }
    return deadplayers;
}

stock TotalPlayers()
{
    new players;
    for(new x=0; x<MAX_PLAYERS; x++)
    {
        if(IsPlayerConnected(x))
        players++;
    }
    return players;
}

This should work fine