mathematica解决填符号使等式成立问题
在网上曾经看到过一个高手用列举法解决一个
(34口5口6口8口9口1)口2=2008
在口中填入加减乘使等式成立
程序如下,但是如果题目要求填入加减乘除和括号,程序要怎么改进啊
比如(5+5+5)÷5+5=8,即5 5 5 5 5=8填入相应符号
info = expr[{"+"},{"-"},{"*"}];
For [a = 1,a < 4,a++,
For [b = 1,b < 4,b++,
For [c = 1,c < 4,c++,
For [d = 1,d < 4,d++,
For [e = 1,e < 4,e++,
For [f = 1,f < 4,f++,
temp =
StringJoin["(34",Part[info,a],"5",Part[info,b],"6",
Part[info,c],"8",Part[info,d],"9",Part[info,e],"1)",
Part
[info,f],"2"]; If [ToExpression[temp] == 2008,Print[temp]]
]]]]]]