NYOJ题目111分数加减法

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需要注意的就是考虑各种情况，各种！各种！！各种！！！各种情况，真是一个让人崩溃但是炒鸡修身养性的题啊....：）

AC代码：

 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 }

题目来源： http://acm.nyist.net/JudgeOnline/problem.php?pid=111