这是我写的第一个程序。网上有很多计算24点的程序，我这个也是先得到操作符的组合，以及输入的4个数的可能组和，先算不带括号的4X4X4X4X24种可能结果，但在形成带括号的算式以验证结果时，（带括号只有（a@b@c）@d,a@(b@c@d),(a@b)@(c@d),(a@b)@c@d,a@(b@c)@d,a@b@(c@d)6种形式不会出现嵌套 ）通过总结得出一个结论：括号中符号不能同时为*，/ 括号周围符号不能同时为+，-；否则括号可省略 于是有了判断各类型的相应代码。-I wrote this is the first procedure. Many online calculation of 24 points, I would be the first of the composition operator, the four input and the number of groups and may, it is not a first bracketed 4X4X4X4X24 possible, but the formation of the bracketed formula to verify the results, (bracketed only (a b @ @ c) @ d, a @ (b @ c @ d), (a @ b) @ (c @ d), (a @ b) @ c @ d, a @ (b @ c) @ d, a @ @ b (c @ d) 6 forms no nested) draws a conclusion : brackets can also symbols for * / brackets around the same time, not for symbols, -; brackets can be omitted otherwise there has been a judgment of the corresponding type of code.