Question

求2的N次方的值，计算表达式为(int)Math.pow(2.0,(double)n) 用JAVA怎么编写

Answer 1

static int cifang(int num){
if(num==0) return 1;
if(num==1) return 2;
if(num>32){
System.out.println("只能存储32次方之内");
return 0;
}
return 2*cifang(num-1);

}
public static void main(String args[]) {
System.out.println(cifang(11));
}

Answer 2

import java.util.*;
public class test{
int i,result;
public static void main(String[] args){
Scanner s = new Scanner(System.in);
i = s.nextInt();
if(i<0){
System.exit(0);
}
result = Math.pow(2,i);
System.out.println(result);
}
}