JZOJ 4742. 单峰

Description

Input

Output

Sample Input

2

Sample Output

2

Data Constraint

做法：打标可以发现这道题是结论题，答案为2^(n-1)，所以快速幂就好了。

 #include <cstdio>
 #include <cmath>
 #include <iostream>
 #include <cstring>
 #define LL long long
 #define mo 1000000007
 using namespace std;
 LL a,base,p;
 LL n;

 inline LL power(LL b){
     a=;
     base=a;
     p=;
     for(;b;b>>=){
         if(b&) p=p*a%mo;
         a=a*a%mo;
     }
     return p;
 }

 int main(){
     scanf("%lld",&n);
     printf("%lld", power(n-));
 }