Applese涂颜色-欧拉降幂公式

#include<stdio.h>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<string>
#include<queue>
#include<math.h>
#define ll long long
#define inf 0x3f3f3f3f
using namespace std;
const ll p=1e9+7;
const ll x=p-1;
 
char a[100086],b[100086];
int c[100086];
 
ll power(ll a,ll b)
{
    ll ans=1;
    while(b)
    {
        if(b%2)
            ans=ans*a%p;
        a=a*a%p;
        b=b/2;
    }
    return ans%p;
}
int main()
{
    scanf("%s%s",a,b);
    int len=strlen(a);
    for(int i=0;i<len;i++)
        c[i]=a[i]-‘0‘;
    ll res=0;
    for(int i=0;i<len;i++)
    {
        res=(res*10+c[i])%x;
    }
    printf("%lld",power(2,res+x));
    return 0;
}
//欧拉降幂公式:在%m时，指数k = k%oula(m)+oula(m)