POJ 1001 Exponentiation（大数处理）

 1 import java.math.*;
 2 import java.util.Scanner;
 3 
 4 public class Main {    
 5     public static void main(String[] args) {
 6         // TODO Auto-generated method stub
 7         /*sss*/
 8         BigDecimal a, c, d;
 9         int b ;
10         Scanner cin = new Scanner(System.in);
11         while(cin.hasNext()){
12             a = cin.nextBigDecimal();
13             b = cin.nextInt();
14             a = a.pow(b);
15             String s;
16             s = a.toPlainString();  //避免科学记数法（如果用a.toSting会存成科学记数法）
17             int start = 0;
18             while(s.charAt(start) == ‘0‘){   //a.charAt(b) 取a字符串下标为b的字符
19                 start++;
20             }
21             int end = s.length()-1;
22             while(s.charAt(end) == ‘0‘){
23                 end--;
24             }
25             if(s.charAt(end) == ‘.‘){
26                 end--;
27             }
28             for(int i = start; i <= end; ++i){
29                 System.out.print(s.charAt(i));
30             }
31             System.out.println();
32             
33             //System.out.println();//subtract-, add+, multiply* divide/ 
34         }
35         cin.close();
36     }    
37 }