NYOJ题目111分数加减法

 1 import java.io.BufferedReader;
 2 import java.io.IOException;
 3 import java.io.InputStreamReader;
 4 
 5 public class Main {
 6 
 7     public static void main(String[] args) throws IOException {
 8         
 9         BufferedReader reader=new BufferedReader(new InputStreamReader(System.in));
10         
11         boolean first=true;
12         while(first || reader.ready()){
13             first=false;
14             String expression=reader.readLine();
15             String ans=solve(expression);
16             System.out.println(ans);
17         }
18         
19     }
20     
21     public static String solve(String expressions){
22         int a=expressions.charAt(0)-‘0‘;
23         int b=expressions.charAt(2)-‘0‘;
24         int c=expressions.charAt(4)-‘0‘;
25         int d=expressions.charAt(6)-‘0‘;
26     
27         char o=expressions.charAt(3);
28         
29         if(b==0 || d==0) return "0";
30         
31         int e=(o==‘-‘)?(a*d-b*c):(a*d+b*c);
32         int f=b*d;
33         
34         if(e==0) return "0";
35         if(e==f) return "1";
36         if(f==1) return Integer.toString(e);
37         
38         int t=gcd(Math.abs(e),Math.abs(f));
39         if(t==f) return Integer.toString(e/t);
40         return String.format("%d/%d",e/t,f/t);
41     }
42     
43     public static int gcd(int a,int b){
44         return b==0?a:gcd(b,a%b);
45     }
46     
47 }