2020牛客暑期多校训练营（第九场）A.Groundhog and 2-Power Representation

2020牛客暑期多校训练营（第九场）A.Groundhog and 2-Power Representation

题目链接

题目描述

Groundhog took a math class. In this class, his math teacher said:

Any positive integer can be represented by the power of $2$. For example:$137=2^7+2^3+2^0$.

And powers are expressed in parentheses.That is ,$a(b)$ stands for $a^b$.Therefore,$137$ can be expressed as $137=2(7)+2(3)+2(0)$.

Further more,for $7=2^2+2+2^0$ is expressed with $2$，$3=2+2^0$,137 can be finally expressed as $137=2(2(2)+2+2(0))+2(2+2(0))+2(0)$.

Another example:$1315=2^{10}+2^8+2^5+2+1=2(2(2+2(0))+2)+2(2(2+2(0)))+2(2(2)+2(0))+2+2(0)$.

Groundhog feels amazing and wants you to write a program to simulate the above content.You need to read in an expression that is a power of {2}2 and calculate its value.

输入描述:

Given a string, indicating the power representation.

输出描述:

Output the original number.

示例1

输入

2(2(2+2(0))+2)+2(2(2+2(0)))+2(2(2)+2(0))+2+2(0)

输出

1315

熟悉 $python$ 的都知道 $python$ 有个 $eval$ 函数可以直接求表达式的值，那么我们只需要把 $($ 替换成 $\ast \ast ($ 即可，因为在 python 中 $2\ast \ast x$ 代表 $x$ 幂，AC代码如下：

print(eval(input().replace('(','**(')))