You don't take someone with no knowledge and teach them enough to pass a Google (or Facebook, or Apple etc...) interview in 12 weeks.
I looked through the curriculum and there is no way, that covering graph theory in a day or 2 is going to teach you what you need to know to pass a Google interview.
From what I can tell after reading up about them it looks like this is what happens:
They make people go through 4 rounds of coding challenges equivalent to something you'd see interviewing as a new grad at a second tier company (not Google, Facebook, Apple, Microsoft, hot valley startup etc...).
Then they take the top 3%. They're aiming for people who are really fantastically good at interviews who already understand the material really well. It doesn't matter that the questions aren't super difficult when they are judging on relative performance.
After that they spend 2 weeks teaching you the basics, 8 weeks teaching you how to use some frameworks, and then 2 weeks teaching you to pass code interviews.
That's not enough time to cover most of what comes up during a Google interview. Professional programmers with years of experience spend months practicing. There are single books on coding interviews that would take longer than 12 weeks to complete.
I'm assuming what comes next is that the graduate spends several additional months prepping for interviews.
So that by the time the person interviews at Google and gets the job they actually have at least a year coding and they're really good at interviewing. This same person could have probably gotten the job without the 12 week course and paying 22% of their first year's salary.
