他把话原封不动转给我：“你看，人家多关心我们一家。”
the concept was well-known in the computer industry. As IBM designed the 2984,
，这一点在Line官方版本下载中也有详细论述
This one was a lot better than others. For every SAT problem with 10 variables and 200 clauses it was able to find a valid satisfying assignment. Therefore, I pushed it to test with 14 variables and 100 clauses, and it got half correct among 4 instances (See files with prefix formula14_ in here). Half correct sounds like a decent performance, but it is equivalent to random guessing.
// 栈空 → 无更大元素，返回-1；栈非空 → 取栈顶（第一个更大值）