http://oj.acm.zstu.edu.cn/JudgeOnline/problem.php?id=4391

题解：快速幂+数学

#include<iostream>
#include<cstdio>
#define LL long long
using namespace std;
LL a,b,c;
LL qpow(LL x,LL k)
{
    LL tem=1LL;
    while(k)
    {
        if(k&1)
            tem=(tem*x)%c;
        x=(x*x)%c;
        k>>=1;
    }
    return tem;
}
int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%lld%lld%lld",&a,&b,&c);
        LL ans=(((a+5)*((qpow(2,b)%c-1)))%c-(5*b)%c)%c;
        printf("%lld\n",(ans+c)%c);
    }
}