取近似值

 1 import java.util.*;
 2 public class Main{
 3     public static void main(String[] args){
 4         Scanner sc = new Scanner(System.in);
 5         while(sc.hasNext()){
 6             double d = sc.nextDouble();
 7             String s = Double.toString(d);
 8             int len = s.indexOf(".");
 9             int num = 0;
10             if(d>=0){
11                 if(s.charAt(len+1)>=‘5‘)
12                     num = (int)Math.ceil(d);
13                 else 
14                     num = (int)Math.floor(d);
15             }else{
16                 num = (int)Math.floor(d);
17             }
18              System.out.println(num);
19         }
20     }
21 }