Agree with 5 day...being a college programmer is the best route to take on earning a side-load. @kinnem
's DS did this and earned a 3 year side-load. He is now a Marine officer.
If you are attending a non-NROTC college, there is still another method of becoming a Marine officer, called PLC or Platoon Leaders Class which is part of OCS. There can be a small stipend but no scholarship by taking this path.
If you enroll as a freshman or sophomore, you would attend two USMC paid six-week summer training programs at the Marine Corps Officer Candidate School at Quantico.
The downside of PLC is that the Corps has no obligation to offer a commission after you are done, although if you do well, they usually will. Remember, Marine officers slots are filled first from USNA, then from NROTC/MO....and LASTLY from PLC/OCS. If the ranks are full from the Academy and NROTC/MO, then PLC slots are usually reduced.
Here is a good source for more info: