First, calculate the number of number combinations that can be opened. Three numbers have only 1 number pairs, 3*7=2 1 number has only two number pairs, and 22 number pairs * * *.
There are 8 * * * 8 = 5 12 kinds of * *, so to ensure that it can be opened, at least 512-22+1= 491combination of common sense is needed.
Because there are 5 12-22=490 combinations that can't be opened, if you only test it for 490 times, you may encounter the situation that it can't be opened (although it is unlikely), and there is no guarantee that it will be opened.