蓝桥春晚魔术（欧拉定理+快速幂）

欧拉定理 p是质数的时候

a的p-1次方等于1模p

import java.util.*;
public class Main {public static void main(String[] args) {long p=(long)(1e9+7);Scanner scan = new Scanner(System.in);int t=scan.nextInt();while(t--!=0) {long a=scan.nextLong();long b=scan.nextLong();long c=scan.nextLong();long n=scan.nextLong();long sum=(((a*b)%p)*c)%p;//计算2的n次方long x=fastPow(2,n,p-1);//计算结果long ret=fastPow(sum,x,p);System.out.println(ret);}scan.close();}//计算快速幂public static long fastPow(long x,long y,long p) {if(y==0) {return 1;}long tmp=fastPow(x,y/2,p);tmp=(tmp*tmp)%p;if(y%2==1) {tmp=tmp*x;tmp%=p;}return tmp;}
}