递推关系式:$A_n=A_{n-1} \times 2+2$
数据范围:$1 \le n \le 200$
答案上限:大约 $2^{200}$
``long long`` 类型上限:$2^{63}-1$
结论:要用高精+递推,黄很合理吧?
by GavinWu_qwq @ 2024-01-02 20:28:19
@[User1246594](/user/1246594)
如果这种题做得少,想要很快找出规律也有难度
by ycy1124 @ 2024-02-21 14:29:59
我觉得评橙合理,因为有效代码只有不到10行
code:
```cpp
int main (){
Bigint fac(1),zh(0);
int a;
cin>>a;
for (int i=0;i<=a;i++){
fac=fac*2;
}
zh=fac;
zh=zh-2;
zh.print();
}
```
其他是高精度实现代码
by fanjiayu666 @ 2024-03-06 13:27:30
c++自带2的次幂高精度,其上限为log log n小于等于14,这个完全可行
by asd890123 @ 2024-04-09 21:28:52